...but if you get hold of "It's Your Funeral", the 11th episode of The Prisoner, you can see Mark Eden (Marco Polo) as Number 100, Derren Nesbitt (Tegana) as the incoming Number Two, and Martin Miller (Kublai Khan) as the watch-maker. Nesbitt is in a strange blond wig and thick glasses, but Eden looks just like in the surviving pics from his Doctor Who appearance three years before. Miller's hair is a bit shorter but it's a surprisingly similar character.
Also Wanda Ventham, who is in The Faceless Ones, Time and the Rani and most memorably Thea Ransome in Image of the Fendahl, is here briefly as a computer attendant, and Angelo Muscat, the recurring Butler, was a Chumbley in Galaxy 4. And for a different cult TV link, Annette Andre, who is the main female character in this story, Number 50, is Mrs Hopkirk in Randall and Hopkirk (Deceased).
Edited to add: see pics from "It's your funeral" here and here.