I think it would be somewhat common to change last names. My last name (Dipert) used to be Deibert around 1800. The pronunciation would sound more like Deibert, but whoever wrote it down forever changed the name. I found the family of Dippert who are related, and a teacher apparently told one of the kids he spelled and pronounced his name incorrectly. My great uncle had last name of Ahnger but on the ship manifest and city directories of Leadville, CO (where he emigrated to from Finland) show his name as Anger. My first wife's family name was Stone--her father's family were French-Canadians whose original name was LaPierre--which apparently means "Stone" in French. And, I have found that the handwritten documents such as ship's manifest are often transcribed incorrectly--for example my grandmother's first name of "Aino" appears as "Amo" on the manifest.