maybe this will work? lightly scuff the surface and then apply.
https://www.amazon.com/Rust-Oleum-26.../dp/B00F87S5KM
i used the same paint on my louvers. it was a pain to get it smoothly coated across the entire surface--took about 4 tries, but your piece is a lot smaller..
here's a picture with both parts in the same light, of course the texture is wrong, but the overall light reflectivity is about the same