The title of this episode would seem to be a pun based on the 1854 song "Jeanie with the Light Brown Hair".
(Ironically, the song's opening line of "I dream of Jeanie" gave the name to the 60s US sitcom which had a similar premise to Pardon My Genie).
Hal discovers that there are other genies, but his own Genie informs him that "alas, there are few us left now, Master."
At the end of the episode, Hal can be seen reading a copy of the Evening Standard dated April 19th 1972. Although the newspaper is just a mock-up, featuring details of the fictitious story in the episode, the date may give some indication of when it was recorded.