I'm not sure what you mean by wanting to fix the census information. I'm guessing you mean in some type of database. But there is no way to change the information on any document that I know of. My husband's Italian relative is on Ellis Island data base with the names reversed, last name first, and there is no way for me to make a correction to that. As it happens, his family is from the Potenza area also, but a different town, Brienza.