Yesterday I purchased the last of my bits. I finally found a cheap vacuum pump that will work well for my brakes, a Volvo vacuum pump. Turns out that their turbocharged cars (and there are a lot of those) all use a vacuum pump for the brakes. Used - $55.
I also purchased a vacuum switch, PB-6 style potbox (with idle micro-switch), pre-charge resistor and a couple of 400A fuses from Cloud Electric.
Today I did some measuring and chopped the motor shaft shorter so it will be about 1/8" from the transmission input shaft when everything is bolted up.
The new coupler should be ready in a few days. I hope. Then all will bolt together nicely. I hope.