* Lois Maxwell also appears in Episode #92 "Simon and Delilah"
* Lois Maxwell was famous for her role as "Miss Moneypenny" in the James Bond films. She also was a good friend of Roger Moore.
* William Sylvester also appears in Episode #62 "The Happy Suicide"
* Paul Stassino also appears in Episode #9 "The Effete Angler", #22 "The Rough Diamonds", #48 "The Death Penalty" and #115 "The Ex-King of Diamonds"
* Paul Stassino is the Vulcan fighter pilot in "Thunderball"
* Robert Ayres also appears in Episode #3 "The Careful Terrorist"
* Patrick Troughton also appears in Episode #30 "The Romantic Matron"
* Derek Sydney also appears in Episode #113/114 "Vendetta for the Saint"
* Hal Galili also appears in Episodes #36 "Sophia", #38 "The Ever-Loving Spouse", #44 "The Revolution Racket" and #113/114 "Vendetta for the Saint"
*
The same extra actor appears in three episodes of the series: Episode
#65 "The Crooked Ring", 
Episode
#68 "The Man Who Could Not Die" and 
Episode
#73 "Interlude in Venice. His name is unfortunately unknown. [Submitted by Wojciech Trojanowski]
*
The arcades in the back are all
painted (0:06).
*
The picture with the yellow sky was used in Episode
#73 "Interlude in Venice" (0:25) and in Episode #75 "The Reluctant Revolution" 
(0:19).
*
The shadow of the boom microphone can be seen on the top of the screen (0:28).
*
The difference between actor Earl
Green and the stuntman is all too obvious (0:30).
*
It looks like you can see the upper end of the set in this shot (0:46).