In my opinion a marine surveyor or a honest boat yard skilled in fiberglass
should inspect the boat before you make any upgrade decisions.

As you may know many boats have frames, stringers, keel, and transom made of
wood then enclosed with fiberglass. When things get mounted to the transom
such as trim tabs, speedometer pickups, depth finder sensors, swim
platforms, etc the fiberglass is penetrated and is a potential place for
water to enter and cause the wood to rot. Keel, frames and stringers
sometimes are not always totally water tight and they too can rot.

Sooo, if your boat is constructed in this manner and many older boats were,
it would be good to know the condition of everything before investing a
major amount of money in a retrofit. This is where the surveyor or marina
comes in to provide that evaluation.

Don Dando