I have an old 1950s theatre programme of the show 'Sauce Tartare', in which Audrey Hepburn is listed among the dancers and Alma Cogan is listed among the chorus; before they were well-known, of course. Is it worth anything?
One of my favourite shops in the whole country sells old theatre programmes (with many of them featuring famous artistes). Select 'theatre', from the drop-down menu here, to see what they sell for:
http://www.kens.co.uk/