Being that I am a very big fan of the variety of knife that is represented by that big fixed blade that you show, I'll try to fill in the facts concerning it. It is a BUCK model 122/124. The 122 and the 124 are the same but with different sheaths. The 122 has a plastic type material diving sheath and is known as a NEMO. The 124 has a leather Flap over sheath and is known as the FRONTIERSMAN. Since you do not show a sheath I cannot tell you which your knife may be. The 122/124s were introduced in 1967. Depending upon the material used as spacers on the pommel it was made between 1967 and 1969. The 1967s had red bone hard fiber spacers and the 1969s had red Micarta spacers. You do have one of the early122/124s and, from my standpoint since I really like them, it is a keeper.
Telechronos

