I am re-finishing a 1979 O''Day DaysailorII. I kept it in fresh water all last summer, and it has been trailered since Sept. ''00. In removing the centerboard this week I found it sloshing with water inside. Upon inspection there is a drilled hole in a location that would not allow complete drainage of the entire centerboard, which has a hollow center. I also discovered leaking holes on the upward edge of the board where two layers were bonded during construction. In re-finishing, should I seal all holes in an attempt to make the hollow cavity watertight or seal up the edge and leave the hole as I found it?