I have a 1974 O'day 20. I've just removed the nylon pin and centerboard. The pin is 1" (25.30 mm) diameter and the hole in the centerboard is 1.22" (31 mm) diameter. When I sail I do feel the movement of the centerboard because of the loose fit. My question is "Was that tolerance designed to allow less stress on the pin, or should there be a bushing in the centerboard for the pin to be a snug fit? There doesn't seem to be any wear around the centerboard hole, but the loose fit does allow for the centerboard to rub up against the inside of the cavity, rubbing the paint of some of the centerboard, but not inside the cavity. I removed the pin and centerboard to stop a leak that I believe is coming from that area.