My first step was to make a foam board mock-up of the three structures. The model is actually based on one on local model railroading legend Gil Freitag's layout. I will try to make mine look like his (his is HO-scale, of course). Also, I am going to build mine in mirror image, because the larger structure has to cover a Tortoise switch machine that still out above the scenery line. I don't know if his is a master craftsman kit or scratchbuilt. I've never had the opportunity to ask him.