It appears Chin became the official boss in 1981, not long after Salerno had his stroke. Prior to that, Salerno may have even been headed for the top slot. In any event, Chin officially replaced Lombardo (who apparently still weighed in on things) and Salerno was acting boss for Chin.
That's right, I read Lombardo disguised his official status for a number of years following his retirement. Law Enforcement officials thought Salerno was the boss, although it later became clear that Salerno was nothing more than an acting boss; there to take the fall for the Genoveses during RICO indictments.
