It isn't that the SS is low grade but that the alloy has to stand up to heat. The materials comprising the alloy and the level of heat determine to color. Leaner mixtures on the same material go blue so later model usually show some blue at the top. Unlike chromed dual wall pipes, stone bruises will never break though a plating and be followed by rust through. The Strom is not a chromed cruiser. If you must treat it as one, stick to the methods mentioned. Never use steel wool. Tiny bits will stick in the surface and the change in metallurgy will cause real rust instead of a protective coat of color.