He would not have lasted five minutes in prison. Willie was of limited use to the Feds because he never got a direct order from Michael Corleone to do anything illegal. The worst he could do was rat out Pentangeli who was one of the family's buffas. I think both he and Pentangeli got imuunity so they could get to Michael, and accordingly WIllie would have gone into the WPP.
Perhaps he took over that Pizza place in Buffalo.
"Io sono stanco, sono imbigliato, and I wan't everyone here to know, there ain't gonna be no trouble from me..Don Corleone..Cicc' a port!"
"I stood in the courtroom like a fool."
"I am Constanza: Lord of the idiots."
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