My great-grandfather was Joseph Eli Mayo, born in Montreal in 1846. For whatever reason, the family knows little of him, but I have long suspected that since he was French Canadian, "Mayo" was probably the anglicized version of his name. All we know of him is that he immigrated to the US in 1870, settling in Alpine County, California where he worked as a miner, store keeper, school teacher, teamster, butcher, and livery store owner. A busy man.Family tradition has it that his family were merchants back in Quebec. It seems the name can't be a coincidence. Perhaps he was an uncle of your Joseph. Do you know of him?