To the op's original question: focus on things that cant be or are very difficult/expensive to change.
- Rust - while its fixable it can be crazy expensive!
- Neglect - this will bite you over and over in ways you likely cant even guess right now. Check any "upgrades" or work done by a PO carefully to ensure it was done right
- Major mechanical issues - run a compression test, listen for clicking birfs, check for a stored CEL (if OBDII), look under the radiator and oil caps, look closely at the frame
- Angst from a significant other - if the timing / cost / condition are going to land you on the couch, let it go!
The reality is pretty much anything else can be dealt with. Its not THAT hard/expensive to add aftermarket lockers, change the color, switch to cloth seats, etc. And be honest with yourself, youre going to be working on it regardless.
Lots of folks get burned buying the one 'right now' but not the 'right one'. Its also tempting to buy one that doesnt pass the first 4 bullets because its close, its cheap, or its immediately available. In the long run those are poor compensators for major items to address down the road.
I believe 80's are (by and large) fully depreciated, so now is a good time to buy. Be aware though that due to their age OEM parts are starting to disappear.
Whatever you choose to do, buy something youll love and enjoy your time with it, hopefully there will be lots, and it will create opportunities for you and your loved ones.
My $.02, ymmv, etc....