Hi Teodor,
To be honest, I missed it too as I was first looking at this, but something seemed amiss, and finally...bonk! there it was.
This piece has all the indicators that it may be one of the multitudes of variant sabres used in the Bedouin sphere, but the scabbard rings were the first clue.
Even more confusing, while this resembles a shashka 'gurda' style blade, which were copied from European forms, it seems more likely Caucasian,although lack of markings seems unusual.
I had suggested a Khevsur sword, which were often roughly furbished by native artisans, but these sabres typically were mounted in regular edge down fashion.
The scabbard throat has the stylized device known by the Arabian term 'aghrab' (=scorpion) and served as an apotropaic in the folk religion as protection against the evil eye. These, as noted, are regularly found on the scabbard throats of the Hadrahmauti sa'ifs which were also used in Yemen. These silvered scabbards, according to Elgood ("Arabian Arms and Armour") were typically produced in Hyderabad, India for export.
The scabbard, as mounted with rings at convex or blade edge upward means that the scabbard was worn with that 'aghrab' inward and non visible. Also, the decorative carrying ring bosses also faced inward. More puzzling is the center section, with crudely fashioned geometrics as would often be seen on the obverse (non visible) side of the scabbard.
Caucasian scabbards are typically decorated on the visible side, and quite plain on the inside.
The hilt, as noted, is intended to approximate the beautiful ivory and silver hilts of the Persian shamshir, the most desirable in the Dar al Islam, however the pommel cap, though beautiful silver, quite crudely done. The wire wrap at the neck, while sometimes seen on Persian shamshirs, is quite typical on Arab, Central Asian and Indian versions of shamshir. It does seem also a Caucasian affectation on some Khevsur examples.
While I cannot place for sure, the motif en cartouche on the scabbard panels seems Caucasian, the bird being one figure that seems to stand out.
I think that this sabre seems rather simply furbished by a village smith, with components and influences at hand. With distinct Arabian characteristics in imitation of the favored Persian style, and features suggesting Caucasian influence and last, the curious positioning of the carry rings suggesting Russian fashion......I think the closest we will come to final answer will be somewhere in the Ottoman sphere.
While admittedly 'speculation by the numbers' , these observations only present possibilities by recognizing these particular characteristics.
When trying to identify the many weapon form anomolies produced in the ethnographic world, we can often only recognize certain features and components that appear in the weapon. Without key markings or provenance, any accurate assessment must remain speculation, with plausible explanations.
Its still fun to make educated guesses!! and this sabre remains a beautiful example whose enigma makes its even all the more attractive.
All tne very best,
Jim