I do have one unaccounted for Leo in my family, but he would have been born in Kremenchug in the Ukraine, not in Lithuania. Since I do not know how certain you are of the Lithuanian birth, I am passing this information on in case it fits.This Leo was the son of my grandfather Leo Ratner's older sister Racheal Leah.She died at his birth (~1884) or shortly thereafter, and the midwife raised the baby.It seems most unlikely that both these Leos had that name in the old country as a baby in a Jewish family would not have been given the name of a living family member. This younger Leo had 3 older siblings who came to the U.S.A. and who took the surname Ratner. And their father Chaim eventually came as well and took the surname Ratner.The younger Leo had a son Gregori who came to the U.S.A. and who also took the surname Ratner and who settled in California.
We do not know what happened to the younger Leo but it seems that if he emigrated to another country he might also taken the name Ratner.However, most likely he stayed behind in the Ukraine and died there.