"The Visitors" sketch is the very first showing all six Pythons playing together in the same frame.
In "The Lumberjack Song", Michael Palin's character says "I wish I had been a girly just like my dear Mama". In all subsequent versions made by the Pythons - including studio albums and the movie Monty Python's and Now for Something Completely Different (1971) - Palin's character always sings "I wish I had been a girly just like my dear Papa"
The Fred Tomlinson Singers played the Canadian RCPM Mounties in the chorus of the Lumberjack song. They later appeared as the singing Vikings in the Spam sketch in Episode #25 and as singing plain clothes detectives in the Sergeant Duckie's song sketch in Episode #22