Hey Okie, welcome back, long time no see. Agreed, cleaning is part of normal preservation and care for our toys. I try to do a light cleaning and oiling (as appropriate) for all items that come into the collection, and about every two years we run through everything and do it all over again. Polishing, never.
This brings up a related subject - this last winter we noticed a contamination - sort of like a "fungus" on some items. Small white spots on bare metals, the same to a lesser extent on some painted metals. Did not seem to prefer one metal over another. Items were due their two year cleaning, so it did not appear to be feeding on any oils (normally WD-40). All contamination wiped right off, nothing has returned in the 8 months since, but we know better than to think it is completely gone. Any thoughts on the source or cures? Internet research gives us a broad list of suspects (40,000 types of mold?) with no obvious culprits or solutions. Not a serious problem yet, but I don't want one either. Seemed to be limited to the first floor which is darker and cooler, an obvious plus for growth, but all areas are climate and humidity controlled.