hi sim
you might look into bookbinding suppliers in the UK.
http://www.google.com/search?q=bookbinding supplies + UK&sourceid=mozilla2&ie=utf-8&oe=utf-8
here in the US we have talas and gaylord brothers and other suppliers of book binding + library conservation materials.
i have some clear pages that i got from talas but they are huge, and i have to cut them down to fit into my books.
it isn't hard to make a book yourself if the ones you find don't suite your needs.
the hardest part is making a cover with a hinge ... and getting the supplies like
the posts and clear pages.
i got my portfolios made for me by
http://www.portfoliobox.com ... they do great work and will work you to make a custom book ...
i have also made my own hand stitched books ( maybe 15 of them ? ) both stab/japanese bound
as well as signature bound. it is fun and kind of addictive
the next one i make ( maybe this summer? ), i plan on documenting the process and writing a small piece for the article section here on apug,
to show exactly how easy it is
good luck!
john