The hoppers on the foreground bridge are a helpful clue. They're full size hoppers only partially loaded over the trucks. Thus, they are loaded with some kind of ore. Based on that, I can narrow down the F7s on the foreground bridge to be Bessemer and Lake Erie units.
The train being crossed over includes an FM C-Liner as the last unit. Based on what little I can see of the paint, it looks like a New York Central engine.
That's about all I can figure out for the time being
Cheers,
Ben