I know when I swapped out my motor on the CVX I rolled some sand paper and gave a few twists to each hole in the transom to clean it out. Swabbed it with Acetone, let it dry for 30 minutes then used a Q-tip with thinned resin to seal all the wood in the holes. Did two coats.
I eased the bolts in and that should keep water from ever getting to the wood via the bolt holes.