Polishing a Micro Seiki RT 3000G Gunmetal platter

I agree with @testpilot   Unless it's been left out in the weather for three decades, I’d be hesitant to take anything resembling sand paper to it.  Pick up any metal polish (check the auto parts store) and combine with elbow grease and a bunch of old sacrificial T-shirts. They’ll turn black as you remove built up oxidation but the platter should shine up nicely as you hand buff it out. A light coat of automotive wax will keep it shiny for a long time. 

What polish do you recommend?

I think Simi chrome (a brand) would be a good start and isn’t too aggressive.

+1 @testpilot 

@horsestuff   What is the platter made of?

Regards,

barts

As a car guy, I was gonna mention Simichrome too, but I thought perhaps it was not quite appropriate since the platter is gunmetal, not aluminum. Simichrome is great for aluminum parts. However, I suspect all of these specialized polishes are similar to one another in composition.