Having tried to research any Counts Ospenniy, my conclusion is that there are no Counts Ospenniy, only an untiled noble family. A few Russian random websites refer to Catherine the Great conferring a comital title on the vaccine provider, but they most certainly exaggerate. Comital titles were severely limited and only conferred in rare circumstances (and never on commoners unless they had shown exceptional merit), while nobility was conferred rather liberally. Google Books give a few glimpses into noted German nobility genealogist Detlev Schwennicke's listing in "Europäische Stammtafeln" of the Ospenniys being "Orlov bastards". No idea where this claim comes from, but it's enticing when you know the connection between Catherine II and Count Orlov.
In a way the connection between Eleonore and this Ospenniy sounds a bit like romantic fabrication trying to link her destiny to Bulgaria, Bulgaria's protector Russia and her distant relative Catherine II as a pioneer nurse, considering that this alleged fiancé with his imperially vaccinated ancestry died in Bulgaria (Телиш) in a Russian war that resulted in Bulgaria's national liberation. Compare this to the claim in her Bulgarian Wikipedia article, which has her first cousin Grand Duchess Maria Pavlovna the Elder visiting Sofia to attend the unveiling of the Statue of Alexander (II) the Liberator (of Bulgaria) in 1907 and recommending her unmarried Reuss relative to the widowed Tsar Ferdinand!
I hardly think a noble, but untitled Russian officer (presumably) would be considered a suitable match even for a minor Reuss princess. Perhaps that's the reason why the engagement (d'inclination?) only lasted one day? Perhaps her parents (and her cousin Grand Duchess Maria Pavlovna) asked the Tsarist authorities to call him back to Russia to prepare for the war?
