Well, if you're willing to read a "WAG"...here goes.
I have a knife (pictured below) with similar scales and a similar stamp and pattern number.
+It has Delrin handles, like yours' appear
to be...so that makes it at least
early '60s, when folks began using Dupont Delrin for handle material. However, if they (the handles) have pores, and are bone.....then maybe that is a clue.
+The 4 digit numbering doesn't match up with older numbering for Kabars.
+Cole National bought Kabar in 1966...so I'm going with after
1966 at the earliest.
Maybe a contract knife made FOR Kabar after they quit making their own knives in the '70s.....but that is just supposition on my part. Also, it is interesting that your knife has only the backspring pin and no others. Maybe that will trigger further information from someone else??