I quickly recalled tonight that I really fucking hate the shift coupler cover - it took longer to sort of get it installed than it did to install the transmission and subframe. Dumbest fucking design ever...it's not water tight, the seal (even when installed properly) is mediocre at best. I decided to be okay with the way this came together and move on. When I've got more time and patience, I'll circle back and fix this clusterfuck.
The plan for the rear end is to send the spring plates out for replating - I'll use the first set that I fucked up for fit and make sure there aren't any other obstacles. I really want to get the engine installed and started up before the frost hits long-term. There's a chance I might be able to make that happen. One step at a time.