There's a chrome polish called 'Solvol Autosol' that's been around for years and it's probably the best there is. Comes in a tube, available usually in car shops or some hardware stores. It'll even remove the blueing on chrome motorbike exhausts or electric fire reflectors. (No baby oil here!!). I've used it on all metals, and it's excellent. Also use it to remove light scratches from plastics. Lakeland Limited appear to sell the same stuff under the name 'Maas' (I think), but it's about 2 1/2 times the price !