I disagree with Darwin.
The Sticky built's have something that Molded Fiberglass RV's don't have, edges, at least 60+ feet of them that are all opportunities for leaks
. And edge leaks
are much more prone to do inside wall damage than leaks on a typical FGRV might experience. It's edge leaks and panel seams leaks that are the death knell of the stick-built RV.
I say that "Molded Fiberglass RV" means that the outside shell, and usually a lot of the inside pieces, were all made in a unique mold, not from stock materials bought off the shelf or made to order from a supplier. And, BTW: No edges.....
The Toyota based 1993 Winnebago Micro Minnie had basically the same construction. The inside of the walls are usually a honeycomb composite. I have never seen any kind of structural members inside flat fiberglass sheet walls. They do mentions an aluminum frame, but big and heavy is still the watchword.