Saw the dagger today and it was an easy spot on copy blade. Not polished blade, maker mark poor done and 2mm of center of the blades center line.
Rest of the dagger nice aged with dark patina spots, but for my view a very good cast copy.
Crossguard got a K stamp on one side, upper scabbard fitting with the NSFK eagle, but not right in size.

Just take care, when the blade would be better done it would fool many collectors I assume.