The first I recall hearing of Jack Benny was 1980.... "The Final Countdown"

Dad took me to a drive in to see it. The USS Nimitz goes back to Dec 1941 and they pick up an old Radio Wave. You hear the Radio show with Benny aand Rockchester. One of the Commander's says..... Jack Benny??? It's when they realize things are weird. I asked my Dad who he was and he told me an old Comic who went back to the old Radio days.