A bit late to apply now, but this makes it clear that it's a third party produced show, and the back stories are a major part of it. There are contact details, but I doubt they'd be willing to answer the sort of queries raised on here:
http://www.bbc.co.uk/showsandtours/t...he_repair_shop
As was said earlier, the BBC were obliged to outsource a good deal of their content. Lord Reith wouldn't be too upset, didn't he refer to TV people as the fools on the hill?