I'm replacing the four bimini mounts , two on each side , one for up and one for stow position ,with a sliding track system, on my '84 tournament The old stainless screws on the old hinge mounts are seized,I imagine stainless screws and pot metal brackets. Dissimilar metals. Any tricks out there for getting them loose? Too close to gel coat to put a torch on. I will use tef -gel when I put it back together. Getting her ready for N.C. deep trolling for trout . Thanks.