Here are some titles that you might want to look into for your project. Salisbury & South Wiltshire Museum: MEDIEVAL CATALOGUE PART I* (there are 3 parts)
THE MEDIEVAL POTTERY INDUSTRIES AT STAXTON AND POTTER BROMPTON, EAST YORKSHIRE (Yorkshire Archaeological Journal, Brewster, TCM, Hayfield, Colin -- 34 pages)
MEDIEVAL POTTERY FROM EXCAVATIONS (Evison, Hurst, Dunning; St. Martin's Press, NY NY; 262pp, 1974)
German Stoneware from 1200-1900: Archaeology and Cultural History*; David Gaimster; 430 pages, 1997, (ISBN: 0714105716)
The German stoneware book is excellent for showing the decline in certain pottery industries such as redware.
I will see if I can find the York book when I get home.
Jenn
NOTE: the titles with an * are items that I have.
--------------------
ad finem fidelis