One other note I was going to add, I'm pretty sure the engine block partially under the tarp in one of your photos was from YW #1171, one of a pair of former Union Pacific Alco S-4 diesels YW bought in the later 1970s.? The #1171 had mechanical issues the road knew about before they bought it but then never got around to fixing, and then they very slowly scrapped the unit over the first part of the 1980s.? The engine block was about the only thing left by 1986/1987, and it too vanished a short time later.?