In Underboss,Gravano talks about a Matty Gambino who has a piece of a bar with John Rizzo,a gambino family old timer and Gravano who was with Shorty Spero at the time i believe a colombo.Anyway The Bull says this Matty comes in and abuses everyone verbally knowing noone will fight back because of his uncle Carlo,Gravano finally had enough and threatens to put his foot up Matty Gambinos ass.A huge sit down over this occurs with Persico telling Sammy the Bull he did the right thing and from that point forward Matty will come in as a mouse.If this Matty is the same as Manny then he was for sure in the life somewhat having a piece of bars with made members and guys like Gravano who were killers even then.The Senter that was involved in the Gambino kidnapping and killing I have read was kin to Anthony the Gemini twin.