I use most of the clean and some of the glue methods above. Hot melt glue the screw heads flush to keep water out. On rings I use a feeler gauge to get the gaps equal before the final torque applied. As for rails I fit headless nylon rods to the clean receiver top, then apply Marine Tex. Then the base is gently lowered onto the alignment pins and a small flat weight is applied to the rail. Sometimes with release agent...sometimes I just glue it. At this stage of my life "lifetime warranty" and second guessing myself are getting less meaningful.
