I agree with the penetrating
epoxy. its really runny and will seep into any soft wood to make it rock hard. it also helps delamination and cracks. once you start tearing out old coring you open up a huge "can of worms". let it dry, patch it up and use it. dont waste money on expensive
epoxy either, for re-tabbing or re-glassing. if the surface is properly ground down and prepped, boat builders resin will work fine. even a little boat like that can keep u busy all summer(winter) if you want it to be perfect.