My mother's maiden name is Silverstein. Her father's father (Benjamin Louis Silverstein) was from Russia, in Koblin (maybe Koblic). I only have it written on a couple documents and the hand writings are kind of hard to read. I know his father's name and date of birth/death, but nothing about Benjamin's mother or anyone further back. There are no Kuperstein, Klein or Kleindorf's in our family though. If my Silverstein's might be a match to your's you can reach me at firstname.lastname@example.org.