This is a prototype of an Ek Blackmoor Dirk 2000, which was made while Blackjack and Ek were the same company. As you know, that ended when the factory in Effingham, Illinois closed its doors in 1997. The Blackmoor 2000 was most often made with the Blackjack trademark; the Ek ones are considerably scarcer. According to Mike Stewart, Past President of Blackjack/Ek, the ratio was maybe ten or fifteen to one. And all the Blackmoor 2000's were made of Applegate-Fairbairn blade blanks that were left over when Blackjack and Rex Applegate parted company. This knife is marked like ordinary Ek knives--crossed knives and: "Ek/ Commando", and: "1941", the year the company was founded, surmounted by a ribbon with: "Korea", World War II", and "Vietnam", where the knives were used. The right side of the blade is marked: "prototype". And this is a most unusual Ek, and a most unusual Blackmoor 2000. The usual Blackmoor 2000 has three eyelet holes in the handle; the one closest to the blade is one that a pin passes through to secure the knife to the sheath. But this knife doesn't have ANY eyelets! The handle is smooth--you can see where the eyelet holes were, in the handle slabs, but there is no metal visible--the holes have been filled with material that matches the handle. The sheath is an Applegate-Fairbairn sheath, with one important difference--instead of two rivets at the throat, there are two eyelets. We were told that the rivets were used on the production sheaths instead of eyelets because there was more bearing surface on a rivet, to secure the throat. Of course, the Applegate-Fairbairn sheath fits perfectly--it was made to fit this size blade. We showed the knife and sheath to Mike Stewart, and Mike recognized it, and said it was the kind of experiment they did to find different handle-blade-sheath combinations that would make a successful knife.