You could always look for a Borg Warner R10/R11 unit. They are what the gear vendors units were based off of. They were found in cars and trucks from the 40's up to the early 70's. Typically on 3 speed trannies, Some Muncies got them too.
This guy sells parts for them:
http://www.fifthaveinternetgarage.co...counter_3.html
Here's some manuals for them.
http://www.speedprint.com/deves50/doc/bwwiring.pdf
http://carburetor-manual.com/borg-wa...ook-p-322.html