This is where my mind is beginning to race, because I think we can use simple aluminum stock to come up with fuselages that are not only stronger, but lighter than ply reinforced balsa fuselages. The fuselage in the pic is 43" long, and along with 8 bolts and nuts, the weight of the substructure came out to 10 ounces, so your looking at the barebones fuselage ready to stuff and fly at a pound or so depending on what you use for landing gear. Not needing any further strength, any type of plane you want could be shaped around such a substructure or "chassie"...out of 2mm coroplast or foam or even balsa or a combination of them. Since the engine and landing gear are bolted to the aluminum...a cartwheel, hard landing, or even minor crash won't ruin your day.