If your looking at a boat that age, I hope you're planning to strip EVERYTHING out and start over.
Do you know how to wire a boat?
Do you know the difference between JIC and SAE hydraulic fittings?
Have you done any glass work? Do you know the compatibility with polyester, vinyl ester, and epoxy?
Do you have a source for cheap used parts.
Old boat economics 101: If you need to put a lot of new parts in an old boat, you end up with an old boat costing as much as a new boat.
You're better off starting with a trashed boat (good hull) with bad engines/drives rather than no engines/drives. The little parts, pumps, alternators, brackets, mounts, drive & gimbal parts, hydraulics, etc.add up to A LOT of money if bought new.