I like the idea of tracing the frames and maybe dabbling on adhesive to hold the foam and benches together. My idea for the raised town, inside the loop area is to cut it out, glue the foam together, about 3 feet, flip it over on a table and build a new frame on top of it. That way we get it bench as close to the curved edge as possible. Flip it over on a table and fully complete it, wiring and all before adding back to the layout. A narrow strip of thin plywood or foam, that sits on the lower foam, but attached to the upper bench, would support the cliffs, when it is moved. This could be applied to all of the raised areas. The wiring will have to be self contained using holes and a block terminal at one end. See the illustration for a cross section view.