My paternal grandfather changed his name from Bencion (or Benzion) Gilenson to Benjamin Gilson on naturalization in 1928. In his petition for naturalization he gives his date of birth as September 10, 1863, and his place of birth as "Druia, Latvia." (The petition for naturalization gives his first name as "Benzon," he signed it as "Benzion," but the actual naturalization certificate spells it "Bencion.")
At least at some point he was living in Rezekne, Latvia, because that was where my father was born.
The JewishGen Latvia Database has a census of Russia in 1897, showing a Benzion Gilensohn in Rezekne, but his age was listed as 44, implying a date of birth of 1853, 10 years earlier than my grandfather, and his wife's name of Haya Sora does not match my grandmother's name, Mnucha. So I presume this is a cousin of my grandfather, though I have no proof they were even related. There are a few other Gilensohns listed in Rezekne, but no trace of my grandparents. Some of them, though, are listed as "Place of origin: Druja." This implies to me that they all were in some way related to my ancestors.
Anyone with useful information about Gilenso(h)ns please help.