the jib travellers in my javelin are both screwed into the fiberglass backrest above seats on each side of the boat. they are starting to come loose as they have been used for fifty years since the boat was made. i want to secure them. Don't rally ave a way to put a backing plate in, should i slide them and use larger screws and hope i can get another 50 years out of them or should i try putting them on top of the gunnels assuming that has a better core than a seat back does. Thanks for your suggestions.