Ditto on the blue loctite which can be "broken" if needed using a wrench to remove the screws. Like Redhawk wrote, DO NOT use red, that stuff needs to be heated to break it loose. I would not worry too much about rust between the bases as long as you did not rub your fingers etc on those surfaces. At most I might wipe the bases/rings with a silicone rag. Most of the scope bodies are anodized aluminum so rust is not much of an issue there.