Thomas, there is currently a used copy of Denis Gifford's "Entertainers in British Films" for sale on Abe Books for £16 https://www.abebooks.co.uk/servlet/BookDetailsPL?bi=596702351&searchurl=an%3DDenis%2BGifford%26sortby%3D17%26tn%3DEntertainers%2    -it is usually £50-£60