From the photos it looks as if you have a large collection of scale length engines and cars. You also have a larger collection of traditional sized equipment.
I suggest that you try to use a minimum of O-72 curves throughout your track plan so that you can run scale length engines and cars. Some of your mainline curves appear to be a bit smaller than O-72.
I know a person who runs a scale length Lionel Big Boy on O-63 but the overhang is awful. He can't run the engine at all on his inner loop. The bigger the curves the better.
If you didn't have all those beautiful shelves full of trains, I would also suggest that you consider an around the wall layout. Around the wall layouts generally give you more layout space for a given size room. NH Joe
