Unfortunately I've seen this kind of thing many times over the years. Most likely if you started in on "restoring" one of these cars you'd find so many problems that it would blow your mind!
Ever see what one Ronnie Rodent can do to the wiring in a vehicle? I resurrected a Toyota pickup that had only been sitting a few years. 34 wires around the computer chewed and acorns stuffed under the dash and in the exhaust. It spewed flaming acorns for about 6 miles before it started to run well!
Owners like this accumulate rather than restore or preserve. These vehicles are well on their way back to the Earth.
Bruce