Ok, if I’m remembering correctly, it was something like “The Crystal Maze”, some sort of game show based on physical puzzles.
All I can remember is someone who was reminiscent of William Hartnell trying to help and losing a bit of fishing tackle. It may have been in black and white but was definitely seen no later than the 80s.
For some unfathomable reason, I keep remembering this series through the years and its started bugging me. Its one of my earliest TV memories and I just can’t remember anything more of it than what I’ve described above.
There was in fact a very similar show called The Crystal Maze too, hosted by Richard O’Brien (writer of, and Riff Raff in, the Rocky Horror Picture Show), but from your description, it looks like Mangetout has what you’re looking for.
In just 2 minutes, something that has been scourging my memory is despatched, courtesy of the Straightdope, thanks Mangtout
I was going to do what I think is now a usual stunt and add a completely false part to the story and declare it to be broadcast in black and white, but then our TV was in black and white back then…