Nihl, this is an incredibly unique item!! and with remarkably exotic character.
I very much agree with Marius' well described observations, especially with the fact that like many ethnographic weapons, regional classification of 'yataghans' is often difficult. As noted the larger 'eared' examples are typically regarded as Balkan, and within the Ottoman Empire. With those two very broad denominators, it is often hard to define more specific attribution.
While reference material on sword canes and walking sticks is very esoteric, and I dont know offhand of any specialized works, it seems that most likely general antique references might have some insights.
I like your approach recognizing the romantic character of such an exotic and clearly personalized item. It is clearly a case of the Kipling-esque "East meets West' in the combining of the sword cane concept to the traditional yataghan weapon, and very likely signifies colonial times. The Ottomans by the mid to latter 19th century were keen on adopting western ideas, weaponry and fashion. The notion of such a fashionable weapon by a member of standing in Ottoman context or gentleman in European gentry is hard to resist.
You have certainly piqued my interest in sword canes, so now I see another obsessive quest to find more
.........thanks Nihl!!!
Absolutely wonderful item, well done!