Heres an Idea I have been working on..
One involves modeling the east end of the Maine Central between Mattawamkeag and Vanceboro.
In the late 50's up to 1960'ish this was a unique piece of railroad being owned by the MEC with trackage rights granted to Canadian Pacific.
Besides colorful diesels, Steam still occasioned the rails going back and forth between Montreal and New Brunswick, Canada, so it could be a lot of fun to model.
Looking at val maps and track charts however, there isn't much to choose from, most is just passing sidings.
So I picked two intermediate spots inbetween that I felt could be somewhat represented in N scale on a door, only I ran into a problem.
Looking at the image below, you'll see what I mean. The red line indicates trackage that I need in order to complete Kingman, but Atlas RTS won't let me do it reasonably..
Its a 36 x 80 inch door, just for reference, #5 turnouts throughout, and 10" radius curves.
Perhaps I need a bigger space?
Just some thoughts.
Besides, I'm also working on a design for a shelf layout that focuses on Lewiston Lower, in the Lewiston vicinity.
But for continuous run with some minor switching, and great picture taking opportunity, this was 'keag - Vancoboro segment was what caught my eye.

Just some Post Script Notes.
If you run the layout from Kingman ME, counter clockwise to Wytipolock, ME, its actually correct according to the maps, all sidings and runarounds face the proper way.
Wytipolock I believe was a pulpwood loadout (I'm waiting on confirmation)
Kingman had a team track for public delivery and a spur, plus 2 runarounds and a station.