I think too many people put too much effort into restoring pieces that will never be seen by human eyes again. Keep in mind the factory built most things to last through a warranty period of 5 years and that was it! Duplicating factory finishes on items like these is not necessarily a good thing from a longevity standpoint even though the parts are likely to never see moisture again !! With that in mind, when I got my regulators all cleaned up I sprayed them with "cold galvanizing" which, according to various literature, could be subjected to many hours in a salt bath with no negative affect to the part. And now they will literally be "out of sight" and "out of mind".

Just my 2 cents ...