A solid choice
I don't have first hand experience with Vanguards, but have a few thoughts. Solid fiberglass boats don't hide many sins. If there are problems, you can see them. Vanguards had a reputation for being built like bridges. Later Pearsons are quite sturdy, so I have no reason to doubt it. Early fiberglass boats, for the most part, were overbuilt because builders were still learning how to use glass and the reputable ones erred on the side of safety. Hidden problems would be in cored areas like the deck. Any decent surveyor should be able to find core problems. They can be repaired, but depending on where it is and how extensive, it can take some time and effort. Sorry I can't offer more specifics. Good luck getting to the bay!