The Ellis Island name-switch experience was fairly common. My grandfather was an immigrant to the US. My father explained to me that, when his father came over, the immigration officer at Ellis Island simply recorded the first syllable of his last name, which is what we've been called ever since. In the Kazan movie, "America, America," the immigration officer asks Stavros Topozoglou for his name and then simply tells him, "Your name is Joe Arnaz"--not exactly what his parents had in mind when he was christened.