Tyzack History Website
If you haven't found it, yet, any Tyzack researcher should check out Don Tyzack's wonderful website:
http://www.tyzack.net/http://www.tyzack.net/
Don Tyzack is also the author of a book onthe Tyzack family called " Glass, Tools and TYZACKS".The book is out of print, but he has a downloadable pdf version available on the site.