Can someone give me info on my Ek?

[C. STORR]

Hi...I have a knife that I will describe best I can. It was my father's. It does not seem to be too old, maybe mid-80's at the oldest but likely 90's. It is an Ek, with the dull parkerized-type finish (is this called bead blasted?) and factory edge (single edge). It has the Ek logo on ricasso, with "Limited Edition Prototype" lengthwise across the dull edge on the opposite side. The knife is about 10.5" long total. The real identifying factor on this is the handle. It is a black slab type handle only about 3/4 cm. thick with three holes evenly spaced down the length of the handle. The sheath is black plastic (kydex?) with nylon web trim, with a retainer pin that goes right through the lowest hole in the handle (closest to the blade) to secure the knife. There is no true guard on this knife - the handle flows right into the blade. Any ideas or info??
Thanks!