I collect these knives and I know it is Ottoman Turkish from the Black Sea region. It belongs to Laz people. Laz people, today considered a minority muslim community in Turkey live along the Black Sea especially Trebizond area and are excellent knive makers, even today. this style was popular at the beginning o fthe century early 1900s until 40s and even 50s. They have somewhet changed in style but they have a dinstinct style and very detailed and quality workmanship and decorations. If you know Laz Yatagans you know what I am talking about

. These knives arealso known as "bichak" or "saldirma", you can also search "Karadeniz Saldirma" in google and you will see similar knives. My favorite knife type.