Although many of the characters from Penrod and Sam (1937) and Penrod and His Twin Brother (1938) appear in this movie, the only actors not reprising their roles from the earlier films are Frank Craven and Spring Byington as Mr. and Mrs. Schofield, their roles now played by Gene Lockhart and Kathleen Lockhart.
One of several feature films where real life husband and wife Gene Lockhart and Kathleen Lockhart not only appear together, but play husband and wife.
Stuart Holmes (Doctor) and George Regas (Pedro) are in studio records/casting call lists as cast members for their roles, but they did not appear or were not identifiable in the movie.