I hope this might be of interest. In the late 1980s I worked with a jeweler to design a 14K gold Cadillac emblem ring based on a detail I sourced from a wrecking yard. He sketched the design and hand-made the ring for me. This is not a managers ring given out at dealerships. I had the ring made when I was the proud owner of a cherry-red 1962 limo and wore the ring about 5 times to Cadillac enthusiast events in Washington State. As the limo had to be sold some time back I haven't worn the ring in a long time and have decided to sell it. It is a size 7 or 18mm. Please feel free to contact me with any questions on this ring. I have the ring listed for sale on bonanzle.com, an eBay competitor. The ring is easily found by searching the site.