Aircraft Spotters Handbook, Guthman 1943
Here is a WWII-era Aircraft Spotters Handbook published in 1943 by the National Aeronautics Council for use by civilian air observers. This mid-size (5 by 7 inches), 370-page reference book is very comprehensive and covers nearly 350 aircraft from around the world, including airships and rotary craft. Each page describes one aircraft, dimensions, and details, including an illustration and recognition silhouettes.
Its a cool paperback book, and we've found rare aircraft in this book that we never knew existed and some that even never made it into production.
The cover has some wear and a few small tears, but the pages inside appear intact.