Helms 25's have a balsa cored deck and solid fiberglass hull. When you checkit out make sure there are no soft spot on deck. The centerboard is steel. Make sure it isn't a hunk of rust. If the rigging and sails look good, sounds like you can have some fun right away.
Kevin on this board had a 72 Helms he sailed up there with his family. If he sees this thread, I'm sure he will tell you how the boat did in that area. From what I remember it did fine. He also took many overnighters with his wife and two young daughters.
Here is a link of his refit on Youtube