The only appearance of the Village pub which is called, appropriately enough, The Cat and Mouse.
For the first of 7 times, Robert Rietty voices Number 2's opening spiel
The only appearance of the Rover 'worshippers.'
The megaphones used are Tannoy Hey-Loh Mark II's from the 1950's.
This is the only episode where The Supervisor (here played for the only time by Kenneth Benda) is seen riding the "See-Saw Roundabout" in the control room