Just putting this out there to see if there's any interest. I decided to model up a pinball on top of a ring:
http://www.shapeways.com/model/502263/pinball-ring.html
Currently it's a 20.5mm inside diameter, but I can easily make it any ring size. The website will make a real sterling silver part based on 3d geometry you send them.
This is the first design I made (printed in plastic). I don't like how far it protrudes, or how weak it looks standing on the legs, which is why I dropped it down in the latest design above:
pinball_ring.jpg
If anyone has any other requests for something they'd like to see let me know.