Some updates!
The van has always been owned by the Space Force, not an individual. They used it to go into the mountains for training exercises, often towing a trailer with snowmobiles.
The conversion was done by Boulder Offroad Vans and involved putting a Ford front end on the vehicle. The CEL and ABS lights have been on since then and their mechanics have not been able to figure out why--they assume a fuse and say that it is the lights only. The vehicle drives fine, does not leak, and they said they would be okay taking it cross country immediately.
It has always lived in Colorado and there is very little rust.
They replaced it with a new, factory GMC 4x4 because the ride is bumpy on this one, especially for people in the rear. They actually took 3" off the lift to try to fix this. When I asked how fast they drive in it normally he said "75 or whatever the speed limit is".
The dent is from the spare tire swing arm not being pinned one time--no accidents. I should have asked more questions about the battery/alternator situation.
Is this better or worse? I dunno. Thoughts? Diagnoses? Run away?