Report "I have a Krups iron, model 633, with removable water tank. Was unused for awhile, and now the exterior soleplate is very discolored. I tried a polish, then metal cleaner, then Noxin with 0000. It appears to be aluminum. No scratches, but still discolored, and not the nice shiny appearance. Lots of minute surface 'texture' which is still discolored. There is a large screw that's visible after removing the water tank. Don't feel comfortable removing that and going further. I need a GOOD metal cleaner, and possily more abrasion? Or a new soleplate? I don't mind elbow grease, as long as it shows signs of improvement. It appears that it's pitted by salts? Many thanks"