OLOF

Set to 3 different clues across 6 published puzzles, most often “Former Swedish P.M. Palme” — The New York Times, Sunday, 20 June 2010.

4 letters

Every clue on record, most used first

Former Swedish P.M. Palme4 times
The New York Times — Sunday, 20 June 2010
Palme of Swedenonce
The New York Times — Thursday, 2 September 2004
With 93-Across, assassinated European leaderonce
The New York Times — Sunday, 11 August 1996