Question: What actor had varying roles in twenty episodes of CBS's "Gunsmoke" with the actor who was best known  for portraying Marshal Matt Dillon for 20 years?
Sentence (from "Gregg Palmer"): Gregg Palmer (born Palmer Edvind Lee; January 25, 1927 – October 31, 2015) was an American actor, known primarily for his work in television westerns.
Relevant evidence: Yes