As I said at the outset, olivant: Vito is a composite of the five NYC Dons of his era, and certainly contains elements of Bonanno. But the override that makes me think he's more like Costello is that, like Costello, he didn't touch drugs, was tops in gambling and unions, kept peace with the other Dons, and "owned all the politicians." He also chose to retire after an attempted murder. Bonanno was big in drugs, ran afoul of the Commission, was deposed by them, launched a long, damaging war against the other families, and eventually was forced to retire. Michael's move to Nevada was a business decision; Bonanno had a second home in Arizona that he bought mainly because his son and putative heir, Salvatore (Bill) suffered from mastoid infections when he was a kid, and the dry air was thought to be good for his condition.