Oh boy, that brings back a lot of memories!
Great to see you are still working on it. Marias Pass is an exciting place with a lot of action going on, I especially like the region between Conkelly, Whitefish
and Kalispell.
What time frame do you set your route in? If it's an older one, I might have some objects for you from my MSTS project of the Hi-Line sub. Though a few of the objects' prototypes, especially the depots and elevators, are still around today. Well, just drop me a line when you get there and I'll see what I can do. Currently, I already have a few GN buildings and objects in RW. Already published are the GN speed posts (though I think BN or BNSF got rid of these) and an elevator (though from the Butte Div.), still unpublished (but already in-game) are the Shelby depot and engine shed, a steel trestle span based on GN specs (larger bridges, like on the Pass) and an old section house that might also stand in as a flagstop depot.
Cheers and please do keep us informed about your progress.
Michael