Croatia. An Unusual Second War Croatian Air Force Dagger with PTS Dagger Blade

A typical Air Force dagger fittings, both pommel and crossguard in silvered non magnetic metal; grip in white colored synthetic material, slightly cracked; scabbard is made of non-magnetic silvered metal, its straight without dents, showing age and minimal use and marked on a throat "Braca Knaus Zagreb". The blade is what makes this dagger unusual; standard Air Force blade (as is Army, Diplomatic, and others) is approximately 24.5cm long, aprox. 2.5cm wide, and is convex; blade on this dagger is double edged/diamond cross section, 23.5cm long, 2.0cm wide and with pointed, sharp tip; it is marked "Braca Knaus Zagreb", with original leather washer, and slightly rusted; with hangers (these in poor condition due to storage); dagger itself in very good condition and untouched since 1945 (purchased in Zagreb from a family this Summer). The only other type of blade manufactured by Knaus that we are aware of is so called Ustasha - PTS dagger; (some believe it is PTS - Pavelic Body Guard Dagger, while some believe it is a Honorary dagger of Croatian Black Legion). This dagger is extremely rare and seldom found. There are two likely possibilities how did Air Force dagger assembled with Ustasha dagger blade; either by mistake, or at one point during the production no other blade was available. This is first time we have encountered this type of blade on Croatian WWII dagger.