Old Pirate
AMG Classic Car Detailing
If these are original then they should be anodized trim piece's that are a pain to clean up, that's how they we're made back then. The process of anodizing speeds up the oxidation of elemental aluminum to aluminum oxide, creating a so-called dull grayish surface finish. The advantage of an aluminum oxide coating is that it is much harder than aluminum and it creates a durable protective finish over the metallic aluminum and last for many many yrs. If you try to polish a piece of anodized aluminum trim, you will spend hours getting through that surface layer, remember once this happens, please be very careful because the underlying metallic aluminum is extremely soft. Hope this helps you out.