Hi Canyoneer,
There are 2 books out there that are the "bible" for the WF's:
-- Paul Schmid, "The Experts Book"
-- Martin A. Armstrong, "Washington Franklin's 1909-23 (I think 23)"
I've had them both, but lost my Armstrong. The reason why I like the Armstrong book, is that it is like reading a story-- it takes you through the history of each issue, and you end up with a pretty good understanding of why each issue happened, and it's just a fabulous book.
From your original question, I can't recommend this book more strongly for you. It is out of print, it's paperback, and you can find it sometimes on
eBay, or from any of the philatelic literature dealers out there.
Good luck, and if you find mine, please read it and return it! :)
Hope this helps, Ray