I dug a little deeper into my dumped ROM and I think I deciphered the model code list. The relevant code starts at ROM-Offset 0x30C9FA / address $50C9FA:
(this is disassembled by hand, but you get the idea. Use the info below at your own risk!)
.org $50C9FA
4E56 0000 link A6,#0 ;set up stack frame
2F0A move.l A3,-(SP) ;save A3
246E 0008 move.l A4,8(A6) ;pass parameter to get device ID
6100 02F8 bsr $2F8(PC) ;get device ID $50CCFE: CAL_get_instrument_config()
72F5 moveq.l #$F5,D1 ;-0x0B
D081 add.l D1,D0 ;subtract offset for first ID code
7216 moveq.l #$16,D1 ;index 22 is last entry in table
B280 cmp.l D1,D0 ;check overflow
6500 0100 bcs $100(PC) ;branch on error
D080 add.l D0,D0 ;double D0 for table index, because we're addressing words
303B 0806 move.w 6(D0,PC),D0 ;get jump offset word from table
4EFB 0002 jmp 2(PC,D0) ;jump to model code
So, this part gets a jump offset from the jump table immediately following the code. This jump table determines where to continue the code depending on the model ID. 0x0B is the first model ID and is the first table entry:
.org $50CA1E
dc.w $42 ;$50CA60 - TDS2022B $0B
dc.w $60 ;$50CA7E - TDS2024B $0C
dc.w $2E ;$50CA4C - TDS2002B $0D
dc.w $38 ;$50CA56 - TDS2012B $0E
dc.w $56 ;$50CA74 - TDS2014B $0F
dc.w $6A ;$50CA88 - TDS2022B_1G $10
dc.w $7C ;$50CA9A - TDS1002B $11
dc.w $84 ;$50CAA2 - TDS1012B $12
dc.w $74 ;$50CA92 - TDS1001B $13
dc.w $4C ;$50CA6A - TDS2004B $14
dc.w $8C ;$50CAAA - TDS1001B-SC $15
dc.w $94 ;$50CAB2 - TDS1002B-SC $16
dc.w $9C ;$50CABA - TDS1012B-SC $17
dc.w $B4 ;$50CAD2 - TDS2022C $18
dc.w $D4 ;$50CAF2 - TDS2024C $19
dc.w $A4 ;$50CAC2 - TDS2002C $1A
dc.w $AC ;$50CACA - TDS2012C $1B
dc.w $CC ;$50CAEA - TDS2014C $1C
dc.w $BC ;$50CADA - TDS2001C $1D
dc.w $C4 ;$50CAE2 - TDS2004C $1E
dc.w $DC ;$50CAFA - TDS1001C-SC $1F
dc.w $E4 ;$50CB02 - TDS1002C-SC $20
dc.w $EC ;$50CB0A - TDS1012C-SC $21
So, this jumptable jumps to the following code, which loads the model ID from a nearby string table:
.org $50CA4C
24BC 0050C916 move.l #$050C916,(A2) ;TDS2002B
6000 00C4 bra.w $C4(PC)
.org $50CA56
24BC 0050C91F move.l #$050C91F,(A2) ;TDS2012B
6000 00BA bra.w $BA(PC)
.org $50CA60
24BC 0050C928 move.l #$050C928,(A2) ;TDS2022B
6000 00B0 bra.w $B0(PC)
.org $50CA6A
24BC 0050C931 move.l #$050C931,(A2) ;TDS2004B
6000 00A6 bra.w $A6(PC)
.org $50CA74
24BC 0050C93A move.l #$050C93A,(A2) ;TDS2014B
6000 009C bra.w $9C(PC)
.org $50CA7E
24BC 0050C943 move.l #$050C943,(A2) ;TDS2024B
6000 0092 bra.w $92(PC)
.org $50CA88
24BC 0050C94C move.l #$050C94C,(A2) ;TDS2022B_1G
6000 0088 bra.w $88(PC)
.org $50CA92
24BC 0050C958 move.l #$050C958,(A2) ;TDS1001B
607E bra.b $7E(PC)
.org $50CA9A
24BC 0050C961 move.l #$050C961,(A2) ;TDS1002B
6076 bra.b $76(PC)
.org $50CAA2
24BC 0050C96A move.l #$050C96A,(A2) ;TDS1012B
606E bra.b $6E(PC)
.org $50CAAA
24BC 0050C973 move.l #$050C973,(A2) ;TDS1001B-SC
6066 bra.b $66(PC)
.org $50CAB2
24BC 0050C97F move.l #$050C97F,(A2) ;TDS1002B-SC
605E bra.b $5E(PC)
.org $50CABA
24BC 0050C98B move.l #$050C98B,(A2) ;TDS1012B-SC
6056 bra.b $56(PC)
.org $50CAC2
24BC 0050C997 move.l #$050C997,(A2) ;TDS2002C
604E bra.b $4E(PC)
.org $50CACA
24BC 0050C9A0 move.l #$050C9A0,(A2) ;TDS2012C
6046 bra.b $46(PC)
.org $50CAD2
24BC 0050C9A9 move.l #$050C9A9,(A2) ;TDS2022C
603E bra.b $3E(PC)
.org $50CADA
24BC 0050C9B2 move.l #$050C9B2,(A2) ;TDS2001C
6036 bra.b $36(PC)
.org $50CAE2
24BC 0050C9BB move.l #$050C9BB,(A2) ;TDS2004C
602E bra.b $2E(PC)
.org $50CAEA
24BC 0050C9C4 move.l #$050C9C4,(A2) ;TDS2014C
6026 bra.b $26(PC)
.org $50CAF2
24BC 0050C9CD move.l #$050C9CD,(A2) ;TDS2024C
601E bra.b $1E(PC)
.org $50CAFA
24BC 0050C9D6 move.l #$050C9D6,(A2) ;TDS1001C-SC
6016 bra.b $16(PC)
.org $50CB02
24BC 0050C9E2 move.l #$050C9E2,(A2) ;TDS1002C-SC
600E bra.b $0E(PC)
.org $50CB0A
24BC 0050C9EE move.l #$050C9EE,(A2) ;TDS1012C-SC
6006 bra.b $06(PC)
.org $50CB12
24BC 0050C7E9 move.l #$050C7E9,(A2) ;XYZZY (Interesting!)
I have added the strings which the address points to as a comment for your convenience. So, now you can happily chance between model IDs. You're welcome!