I've been selling off some of the less valuable items of my collection via Ebay and, I haven't had any problems until today. For the first time ever -- and after over 100 Ebay transactions over the years -- I had an item taken down by Ebay. The message I received was that it was considered a counterfeit item. The item is a United Cutlery Gil Hibben Double Shadow that I picked up in the 1990s. While I recall picking up the knife from a reputable knife retailer, I can accept the fact that it could be a fake. How can I identify it as a fake?