You folks are great -- the Dutton ref was helpful; I'll hunt for the book (a record too, I gather). There's a bit on the web, and it appears that the verb-forms (art, hast, dost) survive too--http://www.homestead.com/pendle/TWANG.html

For the US, I have a c. 1800 grammar book that lists the forms, but notes that they're only used by farmers and the uneducated (approximate quote from memory).

Adam