Bolted on the half assed adapter I made from the front and back of the booster.
Bolted on the master cylinder.
Cleaned the reservoir out, filled it with fluid, then took the tires off and back bled the master cylinder using the front calipers. There's still air pockets in the rear lines, but they're not bad enough to do any harm.
Right now, the force rod leaves about half an inch of free play in the pedal. Once a good adapter is made, I'll fix all the little issues. For now, it should work. Haven't actually tested it yet, other than making sure I had pedal pressure.
Actually going to test drive it soon.