As a followup. Sanded it down, marked out the holes for the PVC grommet and glued and screwed it down with the 3M 5200. Rock solid and waterproof. With some help from another forum member, got the strips for the mast and a base plastic for mast and this is now better than new and looks professional.
New to this forum, and had mast step issue with my sunfish. This forum and topic has been very helpful.
Mine had cracked at upper 1" of the step, and lost some fiberglass and gelcoat. This lead to a leak in the upper portion of step.
I tried to find balloons of the right diameter, but my local...