As you have threads on several boards, you have had some good bets but keep in mind the destination/purpose of the sword doesn't mean it was produced in the same country.
Cheers
GC
http://swordlinks.com/courtswords/courtswords.html
Also, in the late 19th and early 20th century Bulgaria was a kingdom, and its kings were of the German/Austro-Hungarian Saxe-Coburg and Gotha dynasty. They had cousins at most European royal courts.
https://en.wikipedia.org/wiki/Ferdinand_I_of_Bulgaria
Quote:
"The son of Prince August of Saxe-Coburg and his wife Clémentine of Orléans, daughter of king Louis Philippe I of the French, Ferdinand was a grandnephew of Ernest I, Duke of Saxe-Coburg-Gotha and of Leopold I, first king of the Belgians. His father Augustus was a brother of Ferdinand II of Portugal, and also a first cousin to Queen Victoria, her husband Albert, Prince Consort, Empress Carlota of Mexico and her brother Leopold II of Belgium. These last two, Leopold and Carlota, were also first cousins of Ferdinand I's through his mother, a princess of Orléans. This made the Belgian siblings his first cousins, as well as his first cousins once removed (his father's first cousins). Indeed, the ducal family of Saxe-Coburg-Gotha had contrived to occupy, either by marriage or by direct election, several European thrones in the course of the 19th century. Following the family trend, Ferdinand was himself to found the royal dynasty of Bulgaria.
While there is a remote theoretical possibility that the sword, which was definitely made outside Bulgaria, belonged to a Bulgarian royal at the time, I dont think that this would be the case.
The Belgian or Dutch origin of this sword is much more likely.