Thanks for taking the time to reply. I'm glad you found the information you wanted.
You might be able to get an idea of the books' value (if any) by taking a look at the UK's principal site for secondhand books, to see if anyone is offering them for sale. (Remember, of course, that just because a dealer puts a high price on a book, it doesn't necessarily mean that anyone will pay that much for it. Remember, as well, that condition is extremely important with secondhand books):
http://www.abebooks.co.uk/
Chris