Is there a good place to go for room layout ideas?
Room layouts are much harder to cookie cutter than a 4x8 layout. There are so many variations in size, door, window, closet placement that all one can hope for is piece parts from other round the room types. I continually draw ideas from layouts I've seen in the last 50 years of the Model Railroad, Rail Modeler, Model Railroad Craftsman magazines, in addition to books like the 101 track plan ideas, works by Ian Rice, and just visiting other model railroads. The Model Railroad & Trains site has a layout library, I don't know if they require one to be a subscriber or not to view it. They did not used to, but I've not tried to access it for years.
What I got from posts so far is:
min radius - 24" or better
time period - 1950's-60's
geo location - New England
roster - Alco diesels with some steam
layout style - around the room, with island, possibly double deck
layout size - 17 x 25 minus a 10x10 corner
industries - known (but what are they)
For max layout with that space, considering the 17' wide the limiting factor, and if you can live with 3' isles then I can see a two island, mushroom style fitting.