Doctor Who, if I recall correctly…
Hartnell was replaced a) because they didn’t know the show would carry on. The first episode aired against Kennedy Assassination stuff. b) I believe he was too ill to take the part.
(BTW- By the time “Five Doctors” was filmed, there was another man (Hurndell? Don’t recall) playing Hartnell’s role as the first doctor. So it did happen beyond a furthering plot device. Not going to even mention the Colin Baker fiasco and slapping a wig on McCoy for his regeneration).
To address another point- Sherlock Holmes DID have an image from the very beginning. The large, meerschaum pipe being part of it and the deerstalker another. The Steele illustrations, again working on memory, were very influenced by the actor William Gillette. The other, early factor in Holmes’ appearance, which Basil Rathbone matched, were the early drawings by Sidney Paget (based on his brother, Walter Paget who was supposed to be doing the illustrating)
Cyn