The small John F. KENNEDY BUST is, according to its numbering of 1005, the first mold made after those for the 1962 Seattle World's Fair. (The Seattle ELECTRIC PAVILION, currently in operation at the Seattle Pacific Center, is numbered 1004.) It was certainly made during his presidency, and long before his assassination.
This is the small KENNEDY BUST. A larger KENNEDY BUST was made in concert with the wave of president busts made in anticipation of use at the 1964 "ONE NATION UNDER GOD" show at the Illinois Pavilion. Even though that show, originally planned to have animatrons of ALL presidents, was ultimately cut back to being a show about Lincoln only, I have confirmation from one seasoned collector (and member of the Club-A-Rama) that the large KENNEDY BUST was in fact vended at the 1964 New York World's Fair. The small KENNEDY BUST? your guess is as good as mine.