He made 20 appearances
Darryl Richard and Paul Petersen
Darryl Richard (Born March 18, 1946).
Darryl Richard (born Darryl Richard Rosenberg) is a former child actor who appeared on television from 1955 until 1966. He is known for The Twilight Zone (1959), Suspense (1949), and The Detectives (1959).
He is probably best remembered for the role of Morton "Smitty" Smith, the best friend of the character Jeff Stone, played by Paul Petersen on The Donna Reed Show. He appears in 20 episodes, making his first appearance in Season 4 and continuing through the series finale in 1966.