Below is a table of options available for German-system bassoons. The primary sources are various catalogues from Heckel. Catalogue numbers from Fox and Walter are cross-referenced.

R-t = Right thumb
R-1f = Right fore-finger / Right index-finger
R-2f = Right middle-finger
R-3f = Right ring-finger
R-4f = Right little-finger
R-h = Right hand
L- = Left [digits]

Please contact Michael Sweeney if you have any corrections, clarifications, suggestions, or comments. In particular, any information about Heckel or Fox numbered catalogue items not listed or described below would be greatly appreciated.

-home-

Heckel
Fox
Walter
Description
-joint
finger
hole?
key?
Notes Date
(1)
F#+G# trill connection
butt
no
no
41i [first introduced on 41a] 1870
      F#+G# trill connection bypassing F-key
butt
no
no
Sweeney 2015
(2)
C#+D# trill connection (normal: from high-C-key and C#-key)
wing
no
no
41i [first introduced on 41a] 1880
C#+D# trill connection from high-C-key and high-A-key only
wing
no
no
Sweeney 1980
(3)
high-G-ring
butt
R-2f
yes
no
41i [first introduced on 41e] 1902
high-G-ring with connection from G-key to close high-G-vent
butt
R-3f
no
no
integral with (96)  
(4)
Whisper-key
wing
L-t
no
yes
superceded by (9)  
(5)
single F# tonehole [R-4f F#-key connected to R-t F#-tonehole]
butt
no
no
41y [see also (160) below]  
(6)
C/Eb connection [low-C-key closes Eb tonehole]
long
no
no
41y  
(7)
Whisper-key near I opens crook pinhole (reverse action)
wing
L-1f
no
yes
41y / obsolete  
(8)
Whisper-key, A-key, and extra-key above C-key open crook pinhole (reverse action)
wing
L-t
no
no
41x / obsolete  
(9)
Whisper-key (L-t) and connection from low-E-key (R-t)
butt
no
yes
41i 1905
(10)
E+F# trill-key between I/II
wing
L-2f
yes
yes
41i / see also (28) 0/I  
(10a)
4
110
E+F# trill-key between II/III ("offset")
wing
L-3f
yes
yes
see also (28) I/II  
(11)
8
D+Eb trill-key between II/III
wing
L-3f
yes
yes
41p [first introduced on 41m]  
(11a)
D+Eb trill-key between II/III (11) without extra tonehole
wing
L-3f
no
yes
   
(12)
5
high-D-key
wing
L-t
yes
yes
41p / common  
(12a)
Whisper-key and C#-key 1mm closer to long-joint
wing
L-t
no
no
   
(12b)
keys for R-3f and R-4f 4mm longer than normal
butt
R-
no
no
   
(12c)
L-t keys closer together and closer to the long-joint for very small hands
wing
L-t
no
yes
   
(13)
15
second low-Eb-key
long
L-t
no
yes
41p  
      second low-Eb-key also closes low-D-key
long
L-t
no
yes
Kovalchuk  
(14)
F/Ab tremolo key
butt
R-t
yes
yes
41p  
(14a)
F/Ab tremolo key (14) without extra tonehole [F-key (R-4f) closes G#-key (R-t)]
butt
no
no
   
(15)
11
101
Ab+Bb trill-key, elevated above F# and G#
butt
R-t
yes
yes
41p / common  
(15a)
11
Ab+Bb trill-key, between F# and G#
butt
R-t
yes
yes
rare  
(15b)
11
Ab+Bb trill-key, in place of G#-key [see (95)-I]
butt
R-t
yes
yes
same as 95 I / rare  
(15c)
11
Ab+Bb trill-key, behind G#-key
butt
R-t
yes
yes
same as 95 II / rare  
(15_)
Ab+Bb trill with extra tonehole, without extra key
butt
yes
no
rare  
11
Ab+Bb trill-key, above Bb-key
butt
R-t
yes
yes
rare  
(16)
 
   
(17)
 
   
(18)
 
   
(19)
26
100
F+G trill key (AKA high-F-key): above high-E-key
wing
L-1f
yes
yes
   
(19)
100
F+G trill key (AKA high-F-key): next to high-E-key
wing
L-1f
yes
yes
   
(19a)
17
100
F+G trill key (AKA high-F-key): above I
wing
L-1f
yes
yes
   
(19)
F+G trill key (AKA high-F-key): between II/III
wing
L-2/3
yes
yes
   
      high-F#-key
wing
L-f1
yes
yes
Moosmann  
(20)
23
covered key-ring plate for III
wing
L-3f
no
yes
   
(21)
 
   
(22)
[extra R-t-key opens R-4f-F#-tonehole and closes G#-tonehole?]
butt
R-t
no
yes
41kl  
(23)
low-D-key with extra tab parallel to wing-joint C#-key
long
L-t
no
yes
   
(24)
extra C#-trill-key R-t plus displaced key for R-2
butt
R-t/2
no
yes
[as on French basson]  
(25)
[Boehm R-4 keys w/out T-Bb, with key for A+B-trill]
R
R-3/4
yes
yes
[as on Boehm clarinet]  
(26)
low-F+F# trill connection [split F and F# keys; R-t]
   
(27)
 
   
(28)
2
F+Gb trill key (AKA high-E-key): above I
wing
L-1f
yes
yes
   
(28a)
4
110
F+Gb trill key (AKA high-E-key): between I/II (with E+F# trill II/III)
wing
L-2f
yes
yes
   
      high-E-key between I/II (flush with E+F# trill I/II)
wing
L-2f
yes
yes
   
(29)
18
Extra low-D-key, R-t (closes low-E-key)
butt
R-t
no
yes
41v / Cuciureanu  
      Extra low-D-key, L-4f, below C#-key
long
L-4f
no
yes
Kovalchuk  
      Extra low-D-key, L-4f, beside Eb-key
long
L-4f
no
yes
Kovalchuk  
      Extra low-C-key, L-4f, beside C#-key
long
L-4f
no
yes
Kovalchuk  
18
Extra low-C-key
butt
R-t
no
yes
Cuciureanu  
(29a)
Whisper-key pad adjustable in height (oval or square shape)
wing
no
no
   
(30)
 
   
(31)
30
106
Whisper-key ("French") below low-C#-key
wing
L-4f
no
yes
41p  
      Whisper-key ("French") above low-Eb-key
wing
L-4f
no
yes
very rare  
(32)
low-B-Bb connection [low-Bb-key closes B-pad without B-key?]
long
L-t
no
no
   
(33)
 
   
(34)
 
   
(35)
 
   
(36)
 
   
(37)
19
low-E+F# trill connection [low-E-key automatically closes F#-tonehole (R-4f)]
butt
no
no
Cuciureanu  
(38)
low-F+F# trill connection [F-key above Bb-key]
butt
R-t
no
yes
41q  
(39)
 
   
(40)
82
104
1 Roller: A-key
wing
L-t
no
   
(40a)
81
103
2 Rollers: C#/whisper-key
wing
L-t
no
   
(41)
80
2 Rollers: C/D
long
L-t
no
   
(42)
2 Rollers: C#/D#
long
L-4f
no
standard  
(43)
2 Rollers: F/Ab
butt
R-4f
no
standard  
(44)
2 Rollers: Bb/G
butt
R-3f
no
   
(45)
78
1 Roller: F#, facing F-key
butt
R-4f
no
   
(45a)
79
1 Roller: F#, facing F/Ab-keys; broad-style [wide]
butt
R-4f
no
see (54)  
1 Roller: F#, facing Ab-key
butt
R-4f
no
   
(46)
2 Rollers: F#/G#
butt
R-t
no
   
(47)
1 Roller: F#
butt
R-t
no
   
(48)
4 Rollers: Bb/E, E/F#
butt
R-t
no
   
(48a)
2 Rollers: Bb - (E-key round) - F#
butt
R-t
no
   
      2 Rollers: Bb - (E-key square) - F#
butt
R-t
no
   
(49)
6 Rollers: Bb/E, E/F#, F#/G#
butt
R-t
no
   
(50)
4 Rollers: E/F#, F#/G#
butt
R-t
no
   
(51)
2 Rollers: E/F#
butt
R-t
no
   
(52)
2 Rollers: C/B
long
L-t
no
   
(53)
2 Rollers: B/Bb
long
L-t
no
   
(54)
(45a)
butt
no
   
(55)
1 Roller: Bb
butt
R-3f
no
   
(56)
2 Rollers: low-C#-key/whisper-key (31)
w & l
L-4f
no
   
      2 Rollers: low-C-key and extra-low-C#-(90a)
long
L-t
no
   
1 Roller: high-C-key (facing A-key)
wing
L-t
no
   
1 Roller: high-D-key (facing C-key)
wing
L-t
no
   
(60-69)
Whisper-key locks for R-t and/or L-t
lock
_-t
no
   
      Whisper-key lock for L-t: split key
wing
L-t
no
  Rauch  
(070)
Lining of wing-joint bore and small bore of butt-joint
bore
no
41i 1889 patent
(70)
Maple (normal) or Palisander (Rosewood)
wood
no
   
(71)
Mahagoni-red / Normal-red / Dark-red / Brown / Black
color
no
   
(72)
Shape: normal German / French / Italian
bell
no
   
(73)
nickel / silver / Sterling silver
plating
no
   
65
gold
plating
no
   
(74)
125
Ring: metal
bell
no
   
(74)
126
Ring: imitation ivory
bell
no
   
(75)
drain in U-tube
butt
yes
  1904?
(76)
lining of large bore: half / total
butt
no
   
(76a)
lining of toneholes: metal / sterling silver tubes projecting in bore / rubber
tubes
no
   
(77)
105
Handrest (hardwood, removable): AI / AII / AIII
butt
R-h
no
   
(77)
Handrest (hardwood, permanent): B
butt
R-h
no
   
(77)
Handrest (metal): CI / CII
butt
R-h
no
   
(78)
Holes in the cup for a seatstrap
butt
no
   
(79)
Guard A: "grand piano" shape over Bb and Ab+Bb
butt
no
   
(79)
Guard B: long, over Bb/Ab+Bb rod with support
butt
no
   
(79)
Guard C: long, over Bb/Ab+Bb rod without support
butt
no
   
(79)
Guard D: short, over Bb rod
butt
no
   
(79)
Guard E: plate over Bb rod
butt
no
   
(79)
Guard F: extra short, over Bb arms
butt
no
   
(79)
Guard G: "grand piano" shape over Bb and F#
butt
no
   
(79)
Guard H: small plate at foot of Bb-pad
butt
no
   
      Guard: c#-trill-key
butt
no
   
(80)
Covered finger toneholes
w& b
no
yes
41t  
(81)
low-F#/E connection [R-t-F#-key automatically closes low-E-key]
butt
R-t
no
no
   
(82)
52
Balance Hanger
butt
no
   
(83)
Brass tenon rings (2)
long
no
   
(83a)
Brass socket for long-joint
butt
no
   
(84)
1
Holding-together device: [above top of wing]
w & l
no
   
(84)
Holding-together device: [below top of wing; facing player]
w & l
no
   
(85)
119
102
Divided long-joint for compact case (bell in two parts, glued)
long
no
   
(85a)
Divided long-joint for compact case (bell in one part)
long
no
   
(86)
199
Cork on the tenons
tenons
no
   
(87)
Adjusting screws
no
   
(88)
Metal (or plastic?) rings in all toneholes
no
   
(89)
29
111
Whisper-key, above Bb-key
butt
R-t
no
yes
   
(90a)
27
112?
low-C#+D# trill: extra C#-key next to C-key (closes C-key)
long
L-t
no
yes
   
(90d)
28
low-C#+D# trill: extra C#-key next to C-key (does not close C-key)
long
L-t
no
yes
   
      low-C#+D# trill: extra C#-key inside position (closes C-key)
long
L-t
no
yes
Kovalchuk  
(90b)
25
low-C#+D# trill: single key
long
L-4f
no
no
Cuciureanu?  
(90c)
low-C#+D# trill: (90b) with second C#-key and tonehole
long
L-4f
yes
yes
   
      (90c) without extra C#-key; automatic venting of low-E
long
L-4f
yes
no
Sweeney  
(91)
second low-C#-key inside position (B and Bb keys above C-key)
long
L-t
yes
yes
41s  
(92)
33
low-E/F connection
butt
R-t
no
no
Schoenbach  
(93)
9
107
D+Eb trill-key R-1f; displaced C#-trill (R-2f)
w & l
R-
yes
yes
   
(93a)
10
D+Eb trill-key R-1f and L-3f (between II/III); displaced C#-trill (R-2f)
w & l
yes
yes
   
D+Eb trill-key R-2f; normal C#-trill (R-1f)
w & l
R-
yes
yes
   
      D+Eb trill-key R-1f above normal C#-trill (R-1f)
w & l
R-1f
yes
yes
rare  
(94)
Braces under/over long key-rods
no
no
   
(95) I
Ab+Bb trill-key in place of G#-key [see (15b)]
butt
R-t
yes
yes
rare  
(95) II
Ab+Bb trill-key [see (15)]
butt
R-t
yes
yes
rare  
(95) III
12
Ab+Bb trill connection without extra tonehole (can be disengaged at will)
butt
no
no
Cuciureanu? / common  
(96)
high-G#-ring (with closing connection from low-G-key)
butt
R-1f
yes
no
Moritz  
16
high-G#-ring (without closing connection from low-G-key)
butt
R-1f
yes
no
   
(97)
G+Bb trill
butt
yes
no
related to 95 III  
(98)
F#+Bb trill
butt
yes
no
related to 95 III  
(99)
F+Bb trill
butt
yes
no
related to 95 III  
(100)
high-A-key/C#-key connection
wing
L-t
no
no
Weisberg?  
(101)
F#-key/whisper-key connection
butt
R-t
no
no
Moritz?  
G#-key/whisper-key connection
butt
R-t
no
no
Sweeney  
(102)
14
second low-C-key: oval or square
long
L-t
no
yes
   
      second low-C-key: recessed
long
L-t
no
yes
   
(103)I
Half-hole mechanism engaged by I
wing
L-1f
no
yes
   
(103)II
Half-hole mechanism engaged by I and II
wing
L-
no
yes
   
(103)III
Half-hole mechanism engaged by [?]
wing
L-
no
yes
   
(104a)
B+C# trill connection, model A
butt
R-1f
no
no
   
(104b)
B+C# trill connection, model B
butt
R-2f
no
yes
integrated with 93  
(104c)
B+C# trill connection, model C
butt
R-3f
no
yes
compatible with 93  
(105)
Hip support (plastic)
butt
no
   
(106)
Ring for seat-strap attached to cup
butt
no
   
(107)
alternate G#-key with independent tonehole
butt
R-t
yes
no
   
(108a)
Long joint 4mm longer at the bottom
long
no
   
(108b)
    Long joint 4mm longer at the top
long
 
no
     
(109)
6
high-A-key/whisper connection
wing
L-t
no
no
   
high-C-key/whisper connection
wing
L-t
no
no
   
      automatic high-B/whisper connection
wing
no
no
Sweeney 2012
(110)
"Map of inside arrangements of instrument cases"
no
   
(110)
42
no alternate Bb-key
butt
R-3f
no
no
   
      no alternate G#-key for R-t
butt
no
no
   
(111)
 
   
(112)
 
   
(113)
Two bocals
bocals
no
   
(114)
 
   
(115)
92
Instrument case: oval / rectangular / short ("Gentleman")
case
no
Heckel oval case no longer available  
(116)
93
Cover (canvas or nylon)
case
no
   
(117)
Second handle on side of case
case
no
   
 
   
(160)
R-4f-F# without tonehole, connected to F# R-t
butt
no
no
Same as Heckel option (5)?  
         
 
   
      connection from high-D-key opens pinhole at reed-end of bocal
bocal
L-t
yes
no
Grossman  
         
 
   
L-t whisper key is a lock that is opened by the high-C and high-A-keys
wing
L-t
no
no
41z / obsolete  
      automatic venting mechanism ("No-Flick" system)
wing
L-t
yes
Weisberg  
      automatic octave-vent mechanism (high A to E fingered with A and C# keys)
wing
L-t
no
no
Weisberg  
      high-E-key (O/I) and F#-trill-key (I/II) recessed for closer access
wing
L-
no
yes
Weisberg  
      mandrel on band (or elsewhere) for extra reed or reed protection
wing
no
no
Pollard  
         
 
   
      Herzberg modifications
w & b
no
no
Herzberg  
         
 
   
C#-trill for R-1f and R-t
butt
R-
no
yes
41s  
second low-F-key
butt
R-t
no
yes
41q  
single ("universal") key for F#, G#, A#
butt
R-t
no
no
Kovalchuk  
      end pin
butt
no
   
         
 
   
lengthened low-Bb-key
long
L-t
no
no
   
      shortened low-Bb-key
long
L-t
no
no
   
adjusting screw to effect partial closure of low-D-tonehole (and low-E-tonehole)
long
L-t
no
no
   
      low-C#+B trill connection
long
L-t
no
no
   
      low-C#/"S" connection
long
L-4f
no
no
   
         
 
   
         
 
   
         
   
         
   

Thank you to all who have shared photos and information: Saxton Rose, Mikhail Kovalchuk, Ian White, Charles McCracken, Arthur Grossman, and Gerald Corey.