Its interesting to see that a scholar like Astvatsaturian makes no mention of such knives in Caucaus, but I think the niello does look "avaric".
To further justify the melange, city of Trabzon have always had a well sized Armenian, Abkhaz and Turk population; also being a naval trade/commercial city, places on Black Sea like the craft centers of Kuban for example had long established commercial relations.
The dagger does resemble Montenegrean bichaqs but this is looks from further East to me.
Its a very complex piece of work as it in its making it incorporates so many techniques, blade is fullered, incised, inlayed, then the grip is encrusted in similar manner of classic later yathagans, while the scabbard is niello.
It makes me also raise an eyebrow looking at a Ottoman Balkan hilt (but not eared), a Black Sea (oriental Antalya) blade and a Caucasian scabbard; still the reality is that they blend in well visually and its a great piece. Are you sure its not anywhere of a Turko-Greek blend, Yannis? Looks like a bashi-bazouk could have something like this, rather than a Czar's cossack, a hajdouk or a pandur
