I forgot to get back to this, but with respect to Hairy Knuckles, Costello surrendered to serve his tax sentence in Atlanta on October 21, 1958, and remained there until 1961. On June 21, 1961 he finished his term at Atlanta and was driven to serve a 15-day contempt sentence at Rikers Island. Genovese was convicted of narcotics trafficking on April 17, 1959, but was free on appeal. He lost the appeal on January 12, 1960. So from around January 13, 1960 to June 21, 1961, Costello and Genovese were in Atlanta together.

The FBI account of their meeting his here: https://www.maryferrell.org/mffweb/archive/viewer/showDoc.do?mode=searchResult&absPageId=981009