I finally found a transcription of my great grandparents' marriage certificate from familysearch and it has their parents' names. It is a transcription and I am completely baffled by my great grandmother's mother's maiden name. William R. Rumps (should be Romps) married Margaret Marcella on January 6, 1920 in Manhattan. Margaret's father is Angelo, and her mother is Grazia Yvsso. Haven't found censuses from before Margaret was married yet, but the ones I've found say both her parents are from Italy.
What I'm asking for are suggestions for what the name might actually be. So far I've struck out with Yusso and Russo. I'm gonna try Vozzo next.