35 years ago Wednesday, "The Busters," Episode #633 of Gunsmoke (prod. #0672, first aired 3/10/1975), was repeated @ 8:00 (EDT) on CBS. With this retelecast, the venerable Western called it quits after a magnamous 20-season (1955-75), 635-episode run; its former timeslot would be bequeathed to Mary Tyler Moore spin-offs Rhoda and Phyllis.