there is not much to the 5.0 (early to mid-80s hulls are stringers, I don't know about newer), just make sure the hull/deck area feels pretty stiff and look for damage. The online stores here and at murrays.com have lots of Nacra parts, if by mast tensioner bar you mean the post that the mast sits on it is around $50, if it is the dolphin striker V-bar then I don't know.