This is the ONLY one of these I have ever seen. We purchased it in Black Hawk, Colorado (just west of Denver) in the early 1970's. I had some "history" about this piece as it had been owned by a family of prominent "educators" in Denver. An antique shop in Black Hawk was handling the disposal of some of their antique glass. Unfortunately I can't seem to locate the name of that family. I remember doing some succssful searching in a library in Denver.