I think it would be nice to see more locomotives that have weathering on them. Not harsh weather but everyday up and down the road weathering.
I'd agree with this. Just looking at the pics that have been posted since provide some interesting case studies for Weathering. White dust on Black Paint, brown dust on Grey/Blue/Yellow Paint. Rust appearing at the edges of Body Segments (For which you guys have already done very well on some units). There seem to be tons of Factory New Units, and a smaller amount of, though still notable, amount of Destroyed or Heavily Weathered units. But not many, what I'll term, "Casual Use" without looking "Totally abused and neglected" units.....
As for Suggestions....
I'm always looking for more BN, BNSF, UP, and if we want to go a little further back, GN, NP, MLW, and SP&S Units.
2x SD7/9s - GN, Different Paint
NP GP-7/9. Near as I can tell they either didn't have SDs, or nobody took any photos of them that I can find.
MLW SD-7/9s
SP&S Never owned EMD Road units after the F-units. Newest power I think they had had was some Alco RS's and a few early GE Road units.
But whatever's clever.
-Falcus