I had no idea that Elisabeth Sladen was not the first actress cast to play Sarah Jane Smith alongside Jon Pertwee’s Doctor. Apparently not many people knew at all. From Radio Times:
How it could have been: nearly 40 years later, the secret of who was originally cast as Doctor Who’s Sarah Jane Smith has been revealed. It was April Walker, best known for myriad guest roles in Fawlty Towers, The Two Ronnies and Yes, Minister.
Doctor Who producer Barry Letts cast Walker when Katy Manning left the role of Jo Grant, the Doctor’s previous companion, and she worked in rehearsals for The Time Warrior. But allegedly the pairing of Pertwee’s Doctor and Walker’s Sarah Jane didn’t work: she was a tall and more obviously strong character, along the lines of Pertwee’s first companion, Liz Shaw (Caroline John).
It’s believed that Pertwee was unhappy with the decision but it would ultimately have been Letts who recast the role. Walker was reportedly paid for both The Time Warrior and the rest of that series.
Lis Sladen always refused to reveal April Walker’s name, too. But the news has been divulged now on a DVD release of Invasion of the Dinosaurs, the second story with Sarah Jane.
Here’s what Radio Times mocked up to give us an idea what the Pertwee/Walker pairing might have looked like:
Walker certainly has a similar look to Katy Manning’s Jo Grant (though this image of Walker isn’t from DW, and she may have looked quite different in character; I wonder if we’ll ever see any of her footage). Which could be a bit of a problem — you want a new cast member to be distinct from the one she is replacing. But too “strong” a character? This is a problem? *groan*
(If you stumble across a cool Doctor Who thing, feel free to email me with a link.)