Interesting! I wonder if the shows were broadcast live, or shot on film, or broadcast live and kinescope recorded? Either way, any recording will be in the BBC archives and you would need to get a copy from them. I can't find any specific details about getting this, except at this link:

http://www.bbc.co.uk/archive/help.shtml#copy

And the mention of £105.75 on another website.

My aunt appeared in the 1984-1990 ITV run, she was a truck driver at the time.