My great grandfather, Ignacy Isadore Pfeffer, was born in Lemberg, Austria in 1884/1885.
We know that this area has traded hands multiple times in the years since his birth and was also known as Lviv/Lwow.
From searches in several places (including Ancestry, jewishGen and jri-poland) we have a name for his mother: Fajga Pfeffer. However, no father was listed in the birth record.
Fajga Pfeffer had multiple children, and most did not have a father listed. Her last two children did have a father listed, but he was not the one listed on my great grandfather's tombstone (Yakov Shmuel-- no last name given).
So we are looking to get a confirmation of the father and a last name for him. What steps should we take next?