How's you're bulkheads? Rotten? I'm in the middle of refitting my O/I and the hull/deck joint been fixed. I took the old rub rail off and glassed the joint on the outside an reinforced the joint with stainless steel
rivets. Took all the old mastic and epoxy
off the joint from the inside and used a round wire brush on my drill and cleaned in really good ( paint
needs to go too) Cleaned it with acetone and used a few tubes of 3M's 5200 between the joint. Don't use to much -it will sag. But if uou do some sections at the time you'll have time to check on it over a period of a few hours. Takes a few days to cure and sometimes it's better to let it sit and get a little harder and keep pressing if in the joint. If you do a good prep work -5200 is considered permanent repair.
Some oc my bulkheads were rotten from all the leaks
from the joints and the rubber gasket
portholes. I did replace most of those. Did cut my headliner
out too- but that's a different story. Good luck