for rebuildng the first fuselage... start by carefully fitting the 3D jigsaw puzzle together. When its all together.. CA it. then glue some 1/4X1/8 strips of balsa over the places that were broken. (I'd use yellow glue and clamp it well... )

Then patch up the covering... can either patch with more covering or with clear packing tape.

That should just about do it. You actually have MINOR damage. (I have field repaired worse than that cabin in under 30 min.)