Hi, the knife is a model 662 "Faithful", and the back side once had Union Cutlery Co. over the present Olean, N.Y. The first six in the model number is for the jigged bone handles, if it had stag handle scales it would be a model 262. I have several super rare ones in genuine mother of pearl and they are 762s. The full designation for yours which may or may not be stamped on the guard (blade side) is 662-5, with the five being for the blade length although when new the blade was 4.5". In my opinion this is one of the most beautiful designs of KA-BAR hunting knives, or any other hunting knives for that matter. ZZY, the 638 "Bearcat" was not available in jigged bone, only stag or wood and did not have pinned handles, the stag or wood being one piece, and the blade design was a bit more stubbier without the very pronounced top grind as the 662 "Faithful"