The character of Roddy Travers was originally played by former Doctor Who actor Patrick Troughton in the first run of the show in 1980 however Troughton died shortly before the return of Roddy Travers was scripted.
James references that the book "The Lion, the Witch, and the Wardrobe" (by C. S. Lewis) "came out two years ago." The book was initially published in 1950, so that plots this episode in 1952.