The dossier scene for this episode is taken from Wheels (1966), with slight edits - this time, Briggs goes straight from Rollin's dossier to Willie's without a rejected agent in between, and Ira Drake's dossier is added after Barney's. In addition, the dossier scene repeats the continuity errors regarding the orientation of Cinnamon's dossier and the presence of a pad underneath it from Wheels (1966).
This episode features the Michaud brothers; Pat Michenaud, and his younger brother, Jean-Michel Michenaud . They were both successful child actors, until the mid-70s, but thIs is one of the very few appearances they made together, and in the same shots.
The British black right hand drive taxi, registration RYN946, will appear again in S2 episode "Operation Heart" set in a different fictitious country.
The den/office/library room is the same one used in The Diamond (#1.19).
The Wilson residence is the same house used for the Drysdale residence in the Beverly Hillbillies.