Here's my '36 PU that I've owned since 1965 and the original type 3-speed trans that was used in Chevy Master cars and light trucks from 1932-36. There are some different versions of that trans case but the internals are the same from '33-'36.
There was an optional 4-speed but it is a huge, heavy, clunky, non-synchronized thing with a "granny" low gear that is of no use in a pickup.
The tandem MC in the photo is a safety upgrade and is obviously not original. It is from a Jeep and was picked for this application for its 1" bore and small size that lets it fit where the original MC mounted.
My '36 looked like yours when started restoring it.
