I think I found the ROOT cause of the problem.
LM324, U1, pin 7 seems to be stuck high. Can't get it to go low no matter what I do to the + and - inputs, pull to ground, pull to V+, whatever. I can get the other 'sections' of U1 to do what I want using the same methods.
Swapped it out with a new one. The output at pin 7 acts like I want it to, as do the rest of them. Can't check it out completely yet, still don't have a high-gain replacement for Q22 on hand.