Yes, Angelo Caruso was the official Underboss to Maranzano. He represented the members who weren't Castellamarese. Caruso wasn't ambitious and became a Caporegime. He had a social club in Brooklyn called the Shoreview. I am not aware of his operations or crew members

This is partly why Bonanno is thought to haven been involved in the Maranzano hit. People don't understand the truth behind how he was elevated. He provideds a plausible explanation in the book on why he wasn't.