92, we find that the Gengerke census shows no other eight digit radar serial numbers, zero or non-zero. It is so very rare, being the only radar known of this series. Stack's Bowers Galleries has been conducting live, Internet and specialized auctions of rare U. World, and Ancient Coins and Currency since 1933. Stack's Bowers Galleries is an Official Auctioneer for several important numismatic conventions, including American Numismatic Association events, the New York International Numismatic Convention, the Whitman Coin & Collectibles Spring, Summer and Winter Expos, and its April and August Hong Kong Auctions.