These trannys are really simple. If you follow the directions in the shop manual it takes less than an hour to disassemble and the same to reassemble. The only critical assembly requires the use of a feeler gauge at one step (free play between a gear cluster and case). I am confident a skilled person could assemble one in less than 20 minutes.
I have this tranny in my '37 and '42. I have owned the '42 over 30 years and at first I looked for a 3 speed, which is synchronized in 2nd and 3rd. But soon I learned to double clutch, and more importantly, to match engine speed with gear speed in whatever new gear I was selecting. I like driving these trucks now as it is part of the charm and character.
Kent
