Here's the rough casting: http://i55.tinypic.com/34sms8m.jpg
I cut the head off a bolt and screwed it through the bell and put the smooth part of the bolt into a large drill press. Someone's moved the collet chucks so I can't find them. So I used the three jaw chuck at about 120 rpm. Since I was applying almost no pressure with the angle grinder, there's no danger of the bell coming out of the chuck. However a collet chuck would be safer. I used a flapwheel on the angle grinder and here's the result: http://i52.tinypic.com/b876ev.jpg
A bit of sanding with sandpaper, and then off to the polishing wheel for a superb polish: http://i52.tinypic.com/k18c8z.jpg
A lot of bells are needed, so we can't muck around polishing for hours!