One must not discount the possibility of mis-spellings on the original records. For several years, in the NYC Municipal Archives, I had searched for the marriage license of my maternal grandparents,  Charles Black & Nellie Cohen, married March 20, 1892.  I even tried using their Hebrew names - Yisrael Yechezkel and Nechama. I finally stumbled on it after using several combinations of spellings. They are listed on the license as  ESRIAL BLOCK and MILLIE COHEN.  Nellie's mother is listed as Mary CHONE. I suspect that some of the clerks in the office were, themselves, recent immigrants. On my mother's B.C., her parents are listed as coming from RUSHA.

Also, many times, a Jewish bride and groom only had a religious marriage, without it being registered by the city.