Alum trim....
Check the archives, as I know it's been addressed; but when push came to shove, I decided to go with the most easily reversible way; Carnuba wax. I didn't like the idea of a bad re-anodizing job (I'm in NC! Who could do it at all?), a poly-something top-coat that may yellow, and pit with any piece of grit, rocks, etc; it's plastic, right? With wax, I can always buff back out with Mother's Aluminum Polish and re-wax. In hindsight, I wish that I had poly'd the back-side, however. Just my 02 cent's worth. Dave V. in western NC