Cleaning aluminum slots

the more you sand them,and with course,to fine sand paper,the more they will shine.the centerlines on the yellow dart below,were extrmely oxidised,for sitting for many years.I started with 180 grit dry,then went to 320 wet,600,1000,1500,and finally 2000 grit wet.The power balls werent out yet,so i used my buddies electric buffer,and an old buffing pad with mothers aluminum wheel polish,but found it actually worked better by hand http://www.flickr.com/photos/tobysoldblue/1608004328/