Assume you have added access ports, this is the only way to get inside to repair. Suggest you build up with glass cloth and resin, inside the boat, same as factory. Probably should have wings on as you do this to make sure they are lined up correctly. You can not add any material in the holes, and still get the wings on. We have repaired holes in the bottom of the wing sockets by adding glass and resin from the iside of the socket. Any excess resin can be removed by using sandpaper on a broom or similar wood handle. The wing sockets usally break from improper wing removal. You must keep them even on removal, can't just pull out one.
Caleb Tarleton H-17, 144 and 6185