I slammed everything back together and made another attempt at rebuilding the alternator. The only thing I changed was pressing the rear bearing in a little further. That shouldn't have made any difference at all in terms of charging though. Bust. Battery light is still on. I have 11.7V at both the alternator and battery. I probably fried something while I was soldering in the new brush assembly.
The car ran a million times better though. I'm willing to say it ran better than it ever has. Super responsive, smooth idle, no goofy sounds.... except one. The downpipe was still shooting water out of the bottom of the downpipe. At least the oil drain leak was fixed? I decided to try those bigger springs, and waddya know? It sealed!
...but
my turbo in fact did NOT seal against the header.

I immediately bought a new remflex gasket. Although my buddy seems to be happy with his copper gasket, I'm not sure that's even enough to seal up these pits.
I'm trying not to get overwhelmed AGAIN, but this progress is not going as quickly as I need it to. In fact, I might later claim that there was no progress at all. The turbo will most likely need to be removed from the drain to throw that gasket in there, and who knows if it will seal a second time. As for the alternator, I don't think I have the energy to mess with that anymore. I'm very tempted to drop it off somewhere and play with the turbo and master cylinder while I wait. The ugly reality is that Nationals is in three weeks but I have much less time to get this thing done if my wife is going to drive it down to Bowling Green by herself. I'd say it needs at least a week of trouble-free daily commutes to work. Tick tock MF!