Have you ever tried Flitz polish . I've been using it for years , and I think it's the best stuff I've ever used . Not only will it remove rust without hurting the finish , it also leaves a protective coating on the metal . It also works great on guns ,too . It will remove rust , without hurting the bluing . If you can't find it where you live , you can get it from
Welcome to FLITZ USA! : Flitzusa.com, Flitz Metal Plastic and Fiberglass Polish! . BTW , I don't sell Flitz , and I'm not connected to the company , in any way . I just think it's a great product .