Boomer0622,
Well, here is an S through the corner area using O54 and O42 set on 5.5" center rail spacing. I believe that you can have 1' wide shelf width on the long walls, although, it could get tight for overhang.
Just the first concept to try a solution. The grid is 12" blocks. A 16" shelf should handle the outside corner. I think I have to push the inside turn at the top closer to wall, like the left side. It is about 2.5" on the left to stay on a 12" shelf. I don't know if the train will hit the wall with that clearance.
I would use O54 on all of the outside curves (those closest to the wall) and O42 inside to create a double main.
You should only need to cut some fitters at the ends of the straights to fit the curves in the corners and maintain the center rail spacing. Half straights and smaller.
How do you want to fit it or build it? What wall clearance will work?
