You will never see another like this one!! I have never seen another NOS one offered. Has the red spacer which indicates 1953 or slightly after production until 1995. Bottom of knife says… MERCATOR-GERMANY CAT logo one side only! Been in a air tight bag and in gun safe for 50 years Please check out id on blade, both sides and location of rivets against any post WW2 old knives like this one!!! Truely a major Collector Find! NOTE: Mine has the RED insert at lanyard end from 1953. The Black Cat K55K is a great knife, I have about 10 of them right now. You can find them with all kinds of advertising on them and in many different colors. A few years back I contacted Otter-Messer the new owners of the Mercator Brand about how to date the old knives. Here what they told me. Otter-Messer bought Mercator from Kauffmann in 1995, Kauffmann owned the Mercator brand from 1856 to 1995. Kauffmann is now a division of Otter-Messer. From 1891 to 1952 the edge and tang of the Mercator Knife was marked Mercator D. R. G. , which means Deutsches Reichs Gebrauchs Muster. In English, this means “Protected Patent under the Reich Government”. The D. R. G. Markings on the handle side used from 1891 until 1952. In 1952, the patent stamping was changed to Mercator-Germany on the side of the handle. WW2 era Mercator’s are always marked D. R. G. M on the side of the handle. Post-War 1953 and newer knives always have “Mercator-Germany” on the side. The knives that were made pre-1952 were also about a inch larger than the Mercator’s made Post 1953. Also from 1953 to 1995 the spacer inserted at the rear of the knife was red on most of the knives, after 1995 it was change to black, this was done right after Otter-Messer bought the rights from Kauffmann.