I didn't have to do much to my NexSTAR until I crunched the landng gear, then all it took was some epoxy and fiberglass sheeting and it was back to flying. Perhaps some areas you might want to put a little thin epoxy are in the corners of the firewall. Mine took a bit of a beating but never crashed, other than running it into a ditch after a nice landing.. that's what broke the main gear.. turned left instead of right and went into a shallow ditch where it abruptly stopped pushing the left gear back into the fuselage a couple inches.