Gregory Harrison Logan's Run Signed Autograph Photo. Gregory Neale Harrison (born May 31, 1950) is an American actor. He is known for his role as Chandler in the 1987 cult favorite North Shore and as Dr. George Alonzo 'Gonzo' Gates on the CBS series Trapper John, M.D. 1979-85. Photo has been signed on the front by Gregory Harrison. Photo and autograph are in very good condition!