New floor for an old Casita

[jamesguest]

I gutted my '86 Casita today and it definitely needs a new floor put in. Some of it had been replaced but the orginal OSB under the cabinets was completely rotted into osb dust. I found a few cracks where the back of the trailer sits on the frame and there are multiple penetrations through the fiberlass floor. My plan is to strip the wall carpet then take the shell completely off the frame so I can get to the cracks and paint the frame as well. I'm looking for any tips on the best way to patch the holes in the fiberglass, replace the plywood floor and reattach the frame.