I can fill in some of the "pre-1960" ones...
Massachusetts - Middlesex since at least 1960 (despite never voting for Reagan)
Middlesex was last off in 1952, at which time it voted for Eisenhower with a margin 14.27% when the statewide margin was only 8.76%, a differential of 5.51%.
So Middlesex is since 1956.
New Jersey - Burlington, Passaic since at least 1960
Burlington was first off in 1956, when it voted for Eisenhower by a margin of only 22.23%, while the statewide margin was 30.45%, a differential of 8.22%.
Passaic was first off in 1956, when it voted for Eisenhower by a margin of only 23.59%, while the statewide margin was 30.45%, a differential of 6.86%.
So both are since 1960.
Iowa - Poweshiek since at least 1960 (it's tiny, too!)
Poweshiek was last off in 1928 (!) when it voted for Hoover by a margin of 30.32% when the statewide margin was only 24.20%, a differential of 6.12%.
So Poweshiek is since 1932.