I've just remembered that this, one off, programme which I remember watching as a 15 year old in 75, had a pie fight scene, involving Deborah Watling, who was quite fit at that time.
I can't find on YouTube, and the programme wasn't very good, a bit unusual as I was a fan of Les Dawson.
I never knew about this (not surprising as I was negative-five when it aired, but I've never known about it all, despite having other pre-me things like The Dawson Watch on DVD) and Ms Watling does indeed look fit AF in the stills I've just seen.
The show itself is included on a DVD set from Network of various Dawson at ITV projects - will add that to my next order from them!
EDIT (HAVING SEEN CLIP LINKED BELOW): Okay, perhaps I won't order it. She takes a wonderful hit, but - CURSES! - it's in black and white and intentionally graded to look vintage, neither of which work for me. But it was very nice to see it, at least - thanks for the link!