Carlo Gambino was a captain in his late 20's when the commission was set up in 1931. I'm sure he was always respected and considered an earner throughout his time in Cosa Nostra.

Michael Franzese was made a Captain in his early 30's I assume primarily because of his earning abilities as well as being Sonny's son.

John Gotti Jr. was made a captain in his 20's. Although everyone knows that was only because of his father.

The most recent one I'm aware of was Alphonse Truccio with the Gambino's who was a captain of one of the larger crews in that family before being sent to prison.

Meyer I don't think Fat Tony was a capo in his 30's. He was born in 1911 and in the 1940's Trigger Mike Coppola was firmly in charge of that crew as Caporegime. Fat Tony didn't become Capo until the early 1960's when he would have been in his 50's, although no doubt he was Coppola's right hand man and handles things for him.