I don't just make shit up. I'm sure by the time Gravano got the contract on him in the early 80s everyone knew him as Johnny Keys. It was pronounced like keys I'm sure but it was a shorthand form of Cas as in Casablanca. Remember a lot of guys pronounced Gaspipes last name as Kase 0. Not Kass O.

https://www.maryferrell.org/showDoc.html?docId=132534&relPageId=322&search=%22John_Simone%22