Your image of the tool is the one I see in MB-C2. MB-C1 shows a 2 armed puller, but gives the same tool number as shown in your image. Odd.
Based on the image, I would have interpreted the gear involved as being the spiral type mounted to the end of the transfer case idler shaft. I'm not expert but would interpret this as the driving gear and the smaller gear that engages both this one and the speedometer cable as the driven gear. (Both fall in parts group 4.337 so the diagram doesn't make it clear which is which.)
The gear I think of as driving, Chevrolet number1809534, is listed in a Ford parts book as equivalent to C01Q-17285-A and is described as having 4 teeth while a couple of other driving gears with only Ford part numbers are described as having 5 teeth. I think this is the gear you mention on LWD's site:
https://www.lwdparts.com/product/gear-speedo-driven-2/ which seems to be the one listed as being common to the Chevrolet. LWD have another listing for a speedometer gear, driven that is the other part of the speedometer gearing
https://www.lwdparts.com/product/gear-speedo-driven/ Be cautious with terminology to be sure you get what you need.
C01Q-17285-A is listed as appling to F15A, F30, F60S, L, H and FGT. 1809534is listed in Chev parts books as suiting C15A, C30, C60 S, L and X and CG. I didn't check any of the armoured vehicle books.
This gear is listed in the C15A0-04 parts list as one of the * parts, "peculiar to CMP vehicles", but is not so marked in the C60X-04 list. Puzzling.
Most of the non-CMP parts books I have seem to treat the driving and driven gears as items to be ordered as a matched pair rather than individual gears. These sets are all 6 digit numbers instead of 7 digit, suggesting earlier the CMP parts may be later (possibly by being designed to match the transfer case shaft instead of the transmission output shaft as in 2WD civilian pattern trucks. The Modified Conventional Pattern Chevrolets seem to follow the civilian method of treating the gears as "gear unit, speedometer drive".
How badly damaged is your gear? Any chance the driven gear rides on the part that escaped damage?