bench grinder from a carboot = £4 and then take off the grinding wheels and change them for a set of polishing mops that were bought from ebay (you need four different ones and polishing bars and some lime ) check size of mops /polish wheels before hitting buy it now button
learn on a couple of bit of metal/steel/alloy/chrome - heat and time of day can change the way it polishs up - keep every thing clean
put a soft matt under the bench grinder - i use a work horse and have it bolted down - the matt will sofern the item when it pings out of your hands and onto the floor
have fun - watch you eye and wear some leather gloves that can take the heat as a item will get bloody hot
cheers B