I love painting coolermaster cases, nice work on the feet too. Should look real sharp against the back.
Polish though might be hard to keep going, have you thought about using a clear coat?
When I was in the Navy, we had to have our fire stations nice and shiny. Some divisions painted the brass nozzles with clear coat. Completely eliminated oxidation. (I did not however as getting out on deck in the sun was a great way to get off watch
)