More pics: Frame where it kicks up over rear axle taken from near driveshaft looking outward toward frame rails, rear leaf spring hangers (especially by the rear crossmember), bed floor with ambulance doors open, engine/trans/transfer case, engine compartment, front floor pans, dash, seats. Looks like there is mud in that hood, bet there is more in the tub. Worth inspecting closely visually and with magnet to try to figure out motive for repaint. Definitely rust damage but perhaps impact damage, and that'll likely show up at front of frame behind bumper. October 1975 production (late October from Specter's chart) should have disc front brakes but an easy check and see.
No title probably means it is parts in most states, negatively impacts value. Have you looked into getting a replacement title? That process can be a real hassle or no big deal depending on the state, facts & circumstances too, of course. It's probably worth your time to go your state's website and check. Value will depend a bit on location and patience too.
I'm with SergP here, as it sits, $2K tops. Too many unkowns: Engine full of water, out in the weather, stuck, windows in the block, incomplete? There is a reason the engine is out, what is it? Trans and TC shift through gears, boxes not full of water? Frame condition? Interior completeness and condition?
Parting it out is time consuming but would probably yield the greatest net. Or if the motor turns, might be worth the effort to reinstall and get it running. And if it runs, that might motivate you to at least try to get a (legitimate) title. Even if you fail, you now have lots of info that a buyer will want either way, which will help you sell and give you a better idea of value the market may support. It's worth what someone will pay for it, no more, no less.
Sorry for the long post. I hate to see what appears to be a rusty but fairly complete and salvageable 40 end up as parts & scrap. Just my $.02. HTH, and GL!
