Well I looked through the photos again and I see all sorts of little issues that lead more to the slapped it all together.
Looks like rust coming through behind the battery where the hinge is. There is probably a crap ton more hidden behind that. The fuel lines painted over is just sloppy work on paint. Rusted seatbelt, rusted bolts.
I can't tell on all of the pictures but are those rust bubbles being pointed out?
Is that one seatbelt zip tied on lol?
300,000 miles on this, I wonder what it looked like before the "clean up" My guess is those were hard miles.
Loose wires everywhere, unhooks cables, stretched brake lines, look d-shafts...yikers.
The more I look at this I do feel bad. You are in a hard place with this rig. On one hand, since you got it and have been made aware of all the crap that is wrong with it, If you are like me you would have a really hard time selling without fully explaining all the issues you know of and have to take a huge hit.
Unless the body is just bondo'd trash, $8k is too low. I get his premise though. On the other hand, fixing it will cost thousands more as there is a lot wrong from just what we can see from pics/video and it all adds up quickly.
Good call on taking it to Ottram, prepare for the worst lol.
Get it safe (axles/brakes, lights etc) and running without blowing oil everywhere. My guess is you are easily a few thousand in parts and labor here from a shop.
You will have a much better chance selling if mechanically it's much more sound. The body I wouldn't worry about unless it's about to rust through or fall off.
I took a gamble on mine from a friend in another state. It needed engine rebuilt and the price reflected it. That said it pretty much has ZERO of the other issues yours has and was much more taken care of having 300k miles as well.