[mikethedruid]

These chassis become rusty from being stored in a place where they are exposed to unusual damp, someone's cellar or attic, or barn. Some localized rust spots can be from rodent urine. Unless you will be exposing them to continued damp conditions, a little surface rust is really not the big deal some here make it seem. These are radio chassis, not automobiles, and they should never have been subjected to that kind of damp in the first place. If they are not in the future, the rust will not become much worse, it will merely remain as is. A good dusting and cleaning of the urine spots should be enough, followed by a thorough drying. If you remove it, you WILL have to treat the exposed areas because they will begin to rust again. Best would be to completely strip the chassis and re-plate it with zinc. Short of that, automobile primer and then silver paint will do, but be warned, once you paint, or use some similar coating, you will not be able to solder to the metal without sanding away the paint for a clean surface, and the paint on the other side from the soldering will be damaged from the heat. Personally, I don't do any more than the cleaning I mentioned, and guess what ! My chassis are all still there, and have not rotted away to nothing, and the radios I restored work just fine. True, they don't look like new, but they AREN'T NEW. They are antiques.