I have a 59 1-ton and i took the front fenders, headlite mounts, grill, etc apart to sandblast and repaint. I have found that there is alot of rubber gaskets between the fenders, and other metal parts that mount to the cab, are these factory gaskets or some kind of caulk?? they are not very stout, and fall apart very easily. If it's caulk what kind is it that you use to cushion between the metal parts??