I have it very fascinating reading about Jim Hercules because I have begun looking into some of the family history on my mother's side. The timeline of Mr. Hercules in Russia would appear to match a relative I'm trying to find out more of: Josephus Greene was a West Indian from Barbados and also probably had a stay in England. According to my mother and her oldest sister (my aunt), he was well-versed and well-educated. H may have been a sailor for he arrived in Russia and became acquainted with the Russian Court of Nicholas II. The story has it that my great-uncle became a favourite of Nicholas and was invited to Court. In what capacity is unclear, but it may have been something along the line of a footman, valet de chambre or personal assistant. Josephus Greene later married a Russian woman and may have had children, again, I'm not sure. But it was fascinating to read about your search on Jim Hercules and my enquiry on my uncle which, by-the-way: Both timelines are quite close!

Good luck with you search!