thanks guys ...
just bought some 3/8 plywood to put down I just found out home depot has the homosote and a local supply store has it and Cheaper! $27.something for a sheet of 4 x 8
What I thinking is this layout just use the homosote under the track only.. Last layout I used foam I cut to look like a graded bed.. I figure when I add my prefab structures I can blend them in the plywood as needed with foam and plaster to make the look I'm going for..
I'm hoping to have all the plywood and drywall up by this week end .. I'll post some more pictures of that,, and probably the track on it.
Daniel