The Interpretation & Exhibits Programs, Texas Parks and Wildlife Dept, is currently restoring and refurnishing the USS TEXAS, the only surviving dreadnought and the only battleship to have participated in both World War I and II, to its World War II Pacific configuration. The ship is anchored at La Porte (Houston), Texas. We are looking for information on the restoration of stainless steel. Period pieces (1940s) of medical equipment often have lower grade stainless steel components that are rusting in their marine environment. We have tried a combination of sanding and treating rusted areas with "ospho" phosphoric acid treatment. The rust is controlled in this way, however, the acid -- even highly diluted -- etches the finish of the metal. The etching goes deeper than the depth that can be corrected with a buffer and compound. We would like to avoid buffing altogether. How can corrosion be controlled without damaging the appearance of stainless? On a separate question, is the ion exchange method to remove tarnish from metals still valid?