~ STAIN REMOVAL FROM A SILVER-PLATED FLUTE ~ (Yamaha 221)



Problem 1: I've recently encountered several droplets of translucent floating stains which has a wet-look (like oil on blotting paper, or like a beige layer of floating scotch tape) which I'm guessing perhaps is an old oil spillage on the flute, I don't know. I'm baffled. Gentle polishing with silver cloth hasn't helped, a flute bath (above) have not helped. See Photo 3 - oil stain ?
Problem 2: Dark grey marks or welts - broader than usual surface scratches that look and feel like zinc - I looks and feels like the silver layer has been taken off exposing the metal beneath but isn't the YFL221 nickel silver and is that not shiny as well - beneath the plating? Photo 2 - How does one remove this?

Problem 3: Normal scratches - how can one polish these off? OR should one even try to polish these off? Photo 1.