I purchased a piece of brass that is 6" x 48" long. When I bought it the metals company said it had a "mill" finish. So far I have just been trying out different sandpaper to see what it may look like. I have used 800 Crocus cloth ("J" weight) and followed that with 1500 wet/dry paper. (sanded only dry). I still have fine scratches and did a little buffing with brown tripoli which removes some of the scratches but not all. At this point I have only been using a "automotive type" electric buffer.
Any help would be appreciated.