Angib , Thanks for joining us !!! We much appreciate your knowledge and understandings of such things !!!
Actually , it's about a Foam core construction ... covered with Old school canvas skins... fixed with Titetbond 2 inside and out (see the painted model in my Album ) Then Painted... THRIFTY!!! LIGHT!!!
Now the understanding is, we'd need a modicum of wood for high stress areas and "hard points" ... Rock protection is yet to be considered . Doors could be foam if framed with (rot resistant) wood strips for strength and attachment , then skinned. Fiberglass would be too expensive and messy for our taste/ budget..

Just trying to eliminate as Much wood/plywood as possible and the accompanying Rot and de-lamination issues that arose from such use in the past...
This canvas skin business has been proven already by a member that I cannot exactly recall right now (my geezer), and many Old timers. Seems logical eh ... save Hail and Bears

(Guessing you don't have a bear problem )
My 1/4 Scottish heritage demands we proceed in a most Thrifty manner hence this Foam/canvas "adventure" ... ...
