The first place I looked was in the late Anthony Carter's book (including the newest version) and then Fisher. I also have a couple of other sources that I had acquired over the years. I was in correspondence with Anthony right up until his very untimely passing and know to a certainty that some relatively minor verifiable additions did not make it into his book. Which is not a criticism because I'm very glad that John Walters, Henning Ritter, and others stepped forward to finish the book and put it into the hands of collectors. Anthony made a number of trips to Solingen to talk to people and gather information, with my best guess at the moment being that Fleschenberg was just not large enough to get noticed given all of the research and contributor's examples that went writing the references cited. Best Regards, Fred