I had the same marks as yours I tried all sorts to get the marks off but nothing. And I realised I had a cape cod polishing cloth from my old stainless steel version from a few years ago, I was very hesitant to use it I just went over the casing lightly for a few goes and all my marks have disappeared and no gold colouring has come off either. As I say if you do go this route be very careful to just do it lightly.