The bezel I started a few days back was finished off on Monday night and delivered to a happy recipient. The surface was given a very light skim to remove the paint and the ends were rounded off freehand with a round nosed profiling tool and by a bit of fancy handwheel manipulation. This did not result in a perfect finish but a bit of emery cloth smoothed out any imperfections and wirewool and brasso finished it off.
The main reason for mentioning this seemingly simple operation is to tell you a problem that occurs when a piece like this is clamped from it’s internal diameter. As the piece is machined it heats up and expands, this causes it to come loose on the chuck. There are probably more sophisticated techniques for dealing with this but I simply kept tightening the chuck between operations and when it started making noise. I expect that flooding the work with coolant would also have worked. I’d be interested to know if anyone has any other solutions to this issue.