HO train enthusiasts?

I am looking for a site or printed book that would give me an idea of what these boxes of cars/parts are worth. Most are from the late 40's into the 50's. There are some "kits"; some look like balsa wood and others are heavy stock paper for bodies. One batch is possibly stainless steel as they are sleepers and such. a unique item I ran across was a motorized turntable. Opened the box and it is wood with a smaller box of pieces and instructions. As I dig them out and go thru them, I'll post pictures if anyone is interested. Thanks for any help with an unusual request.