We are modeling 1:24th fine scale. You may have seen postings about our 0404 caboose or the no. 42. I do know that all revenue cars were out, we are loosely modeling the transition period of late 30's to early 40's. This way we can have pretty much any paint scheme and still work. It is not strict though as our 42 is based on the early 50's.
Really the reason in building these is more for the quickness and simplicity. All wooden, common parts, no bodies or roofs to install. We have a hand full of kit bashed cars, and now two scratch built cars. This way we can have a basic train, and it be all scratch built.
Casey