I dont know about interior damage per se...it's just not there! I'm sure whatever firepit it got thrown into it was just as rotted as yours
I'm in Ottawa Canada and "Humpty Dumpty" as I affectionately call her is in a local rural area called Almonte. I get cheap storage in the same field I bought her out of and go out when I have time to work on it. Yes, it'll be a Lot of work from the leaking portlights to the stripped off hardware and mismatched mast ( I bought a new one off a cal 20 complete with stays!) but as It's only ever meant to be something to camp out on the water on the odd weekend in the summer, I'm sure it'll be fine. Was only meant as a bit of a fun project, and I dont really care what it ends up costing me at this point. I'll always have more into the boat than its value, but that is boat ownership.