Some HAD to be taken on the east coast, because they clearly show PRR catenary, and a few have GG-1s. Others are clearly Chicago, with a few showing BN switchers. I wonder if he might have been working for Amtrak on one of the NEC-Chicago routes?
He's also answered my question of a few months ago, "How many cars hadn't been repainted in 1974?". It looks like at least one of every GN and NP type Amtrak inherited hadn't been repainted by 7-74, which will make assembling an Empire Builder, or North Coast Hiawatha, easier when Kato's new SDP40Fs arrive. The exact car name I have may not have been unrepainted, but the overall mix will be acceptable.