I Finally got a 24v heavy duty GE motor and the transmission for this car mated! I'm not dead and neither is this project - just very slow
I used lovejoy couplers. One fit so well that I had to hammer it onto the transmission, which sort of created its own splines in the coupler. The coupler on the motor fit snugly, and the key fit directly down into a spline groove. If this coupling solution is to work with these lovejoy couplers, it would have to be in this circumstance because fortunately I don't think I could get either of them to fit any more snug. Next is mounting it in the engine bay - be back in a couple years! :P