Peeking in my steel MK3 original roadster tank, I see smallish patches of rust. Nothing too significant, and I realize this is normal but someday I would imagine it will rust through..... maybe not in my lifetime. Is there a treatment to coat the metal or is the general consensus to leave it alone? Years ago, circa 1978, I had a fiberglass tank and I would use a coating to seal. is there a modern day chemical to address this matter or is current wisdom to leave well enough alone? Simply fishing to see what others have done.