Tim,
It's pleasantly convenient that you have the Prairie Shadows (Rapido-tooled) gondolas available that are prototypical for PGE. I looked at it similarly with the BLMA gondolas being prototypical for Conrail, although I can't use stock models and will have to repaint/decal. I still have to research the motive power and cabooses utilized, but there are plenty of N scale candidates that represent prototypes Conrail owned so I'm not too concerned.