Mitchells was my father's place of work, and his father's before him. At the request of John Randle of The Whittington Press, I wrote my recollections about the business for Matrix 26, which was published in 2006. Some long time after that, someone from the British Association of Paper Historians rang and asked if I minded my article being reprinted. "Not at all," I said, and forgot all about it.
Now, a couple of copies of the BAPH's journal, The Quarterly (for January 2010) have plopped through our letter-box. Re-reading the article, I rather think it should have been re-written!
Mitchells' sample books are now deposited with the Sir Kenneth Green Library of Manchester Metropolitan University, as an addition to their special collection of fancy papers.