I've been thinking about this. I have the specs on the driver but I don't have a lathe or any metal working equipment. I do have a wood shop, still no lathe, and have been thinking about trying to make something out of hard wood. I can cut round pieces on the band saw and make everything except the 0.5 mm relief. I think I can make up some shims to glue around the edges, it doesn't have to be a complete circle, out of metal can stock. After all, it only has to work once.
Thanks
Rod