Almost 40 years after his death following a bar brawl in Key Biscayne, Ricardo Morales, known as “Monkey” — contract CIA worker, anti-Castro militant, counter-intelligence chief for Venezuela, FBI informant and drug dealer — returned to the spotlight Thursday morning when one of his sons made a startling claim on Spanish-language radio:Morales, a sniper instructor in the early 1960s in secret camps where Cuban exiles and others trained to invade Cuba, realized in the hours after President John F. Kennedy was assassinated in Dallas in 1963 that the accused killer, Lee Harvey Oswald, had been one of his sniper trainees.