Looks like I found one of the issues:
Removing the drum, I found one of the return springs
Here's a shot of the adjuster from the inside, you can see how I galled up the teeth trying to break it loose then turning it the wrong direction.
You can also see the amount of shoe material left, should last my lifetime. I already proved it will lock the tires up!
I removed the upper wheel cylinder, there was a small amount of rust inside from air pockets/moisture, otherwise the bore, cups and pistons look like new. A little steel wool and put it back together. I'll grab some more pics tomorrow. I didn't want to disassemble everything until I knew the pics came out to be able to put it all back together.
Do you know if the anchor block is removable? I'm referring to the caliper-shaped block bolted to the backing plate that houses the adjuster screw. Two bolts from the axle rim, one from behind, but then the other end has a pin going through the backer plate. Friction fit, but does not want to come out...