These are as rare as hen's teeth. If you have some good pictures, BGRESTO can make you a brand new one. The art is sprayed on plastic, and then bonded to the glass.
Your situation is different than mine - I had a backglass that was severely flaked - some paint was missing, but the whole glass was there. He used that and made me one that made the owner cry it was so good.
It's pricey and takes a while, but hey, if you need one, this is an option.
Nothing on eBay, but I did find this picture on the rubber ring kit. I knew this was familiar - I rehabbed one of these years ago. It sold for a lot of money at the Immaculate Conception Church school auction.
He may actually have the art on file. See this link: