So, I always assumed the not threading issue meant, well, there were no threads. It's now apparent that I was incorrect and I have a misalignment.. :deeplist: I'd looked past this issue for years while messing with other items on the car and never took the time to inspect it properly.
Yeah, it certainly looks messed up:
Shit.... Even confirmed it by removing another bolt and threading it in, but it goes in canted. I'm simply going to bore the hinge out to 1/2" and use a larger washer.