Help! Looking for expert advice to recondition my air cleaner.

Thanks for the mention @Blind Squirrel. I've restored dozens of old air cleaners through the years but don't recall ever seeing a "factory rust coating" on any of them.

Perhaps a vinegar / electrolosis bath will clean it up some (I media blast).

@cruiser, just one question though. Why would you want to try to preserve this anyway in light of the fact it's now all rusty? It apparently didn't work or you wouldn't be fighting rust now.