There is a good (if rather rustic) set of plans in a book called "Homebuilding and Woodworking in Colonial America" by c. Keith Wilbur. You can find it on amazon.com. The book itself is kinda interesting, including not only "pure" timber frame stuff but also period details (like why oxen were preferred over horses fo hauling timbers, diagrams of a water powered sawmill, etc), but it looks and reads a little like a kids book in places, and all the text is handwritten, which gets hard on the eyes after a while. Still, a decent book with some good info.
