A question for the guys who DO know their rear end from a hole in the ground

[HarveyH]

Howdy All,

I have a WWII military "Light Duty Warehouse and Airfield Tug" that is based on a Ford Model B engine and transmission but uses a worm-drive rear end and wheels.

I know that the Model B didn't have a worm-drive rear end so it's likely an early AA or even a late TT rear end. Can anyone tell me if the first year of the AA used a worm-drive rear end or did it end with the last TT?

Thanks,

Harvey