A little elbow grease

This is a scrap piece of aluminum from my motor plate. I quickly hit it with 320, 600, 800, 1000 grit snadpaper, then rubbed it out with some Never Dull. It’s far from perfect, but I think if I took some more time and used finer grits, I could get it to clean up pretty well. I just need to find a quality metal polish/sealer that will keep it looking good. Any suggestions?