Altobello may or may not have been in the Corleone family, but if he wasn't, he was damned close to them. I don't think Vito would have selected him to be Connie's godfather otherwise.
That's what I think.
I have always believed that Vito was a composite of several Dons, including Profaci (olive oil king), and Bonanno (brings his son into the business). But the one he most closely resembles is Frank Costello, "Prime Minister of the Underworld," who eschewed drugs, dominated gambling and unions, and was the most politically powerful and sophisticated of the Dons.
I very much agree to Frank Costello. Although Coppola at one point said that Vito could be based on Vito Genovese, Frank Costello is probably the primary model for Vito. Carlo Gambino also. But I don't agree about Joe Bonanno. I really think that argument is weak, because Vito could then also be based on numerous other bosses who wanted their son to succeed him. Bonanno is more of a model for Michael.
