I guess I'll chime in.

Mr. Baker's book is a good resource. There are are lot of very reasonably priced catalog reproductions sold on Ebay by Cornell Publications. Just enter in the search box James Dixon, Hawksley, Lightwoods or other names and they will come up. These are excellent material. Not only that, they help you figure out exactly what some of this stuff actually does!
I'm always scouring auction catalogs and books for more pictures. Then I get ideas, and there's always tooling for another tool being developed here. It never ends.....
This website is fantastic (courtesy of Bill Shear):

http://paulcollis.dphoto.com