They are the weathered HO Accurail offerings, not N scale.
Yes, I know. I am trying to imagine them sitting on top of some Proto:87 wheels.

The weak point is the chunky Accurail details, esp the end cages and coupler boxes. (Too bad MT didn't do this with some Athearn Genesis or Tangent models.) It may be worthwhile to try replacing those with some better parts (and maybe the roofwalks). I don't think it would be too hard to blend w/the factory weathering -- it would take a lot of work to hand-weather a car to look like that.
Ed