Edwin Carp's poem "Perseverance" is "It Couldn't Be Done" by Edgar Guest with very minor changes for comic effect. Carp's "Courage" is a similar treatment of "The Giant" by Charles Mackay.
Amzie Strickland, the woman who plays Edwin Carp's mother was, in real life, fourteen years younger than Richard Haydn.
The set used for the pet shop also served as the shoe store set in the S4 episode "Young Man with a Shoehorn".