We have to make some distinctions first like during the late 30s and early 40s Roselli was one of the Mob's guys, not just the Outfit's, in the Hollywood extortion scheme which had nothing to do with Vegas.

Now during the late 40s and early 50s the Outfit's rep in Vegas was Gus Greenbaum who in turn was joined by Marshall Caifano. By 1957 Greenbaum was told to back off and the next year he was brutally murdered possibly by Caifano and some other fella or fellas. Also by the late 50s Caifano had a lot of trouble with the government and so he was replaced by Roselli who as I said previously, possibly transferred his membership to Chicago (https://www.maryferrell.org/showDoc.html?docId=112979&relPageId=41&search=roselli_membership). By 1962 i think Caifano entered in Nevadas Black Book and so he returned to Chicago as one f the bosses around Rush St, thus leaving Roselli in a complete control.

In November 1967, Roselli was convicted of an illegal entry in the country but everything was stopped possibly because of his connections in the agency but in 1968 he was again convicted with four other individuals on conspiracy charges. Sources say that in 1970 Roselli still handled some interests in the Frontier Hotel but began developing some health problems and so by 1972 the Outfit's new rep in Vegas became Tony Spilotro