Here's a image of the rare Secret Agent Field Guide ('65 edition) paperback. Mine is the one on the bottom (white spine), found the other 2 on a Russian auction site. So far I've only seen the solid gun version and the outline gun one, but it seems from some message boards like there was a totally different cover for the 1964 first print hardcover, a orange and green one with a photo on the back. These were classified material back in the day but they are a blast to read now. From the introduction: "It is highly recommended that you disguise your copy of The Secret Agent Field Guide as some other book. A dust jacket from a similarly sized English-to-French dictionary would do nicely. No expensive first editions, as these will attract book thieves.
Once adequately camouflaged, this guide can be brought into the field, even on a seaside vacation or at an amusement fair, anywhere you would like brush up on the basics. We promise that The Secret Agent Field Guide is not the crass product of an armchair-bound committee of sclerotic killjoys, bent on milking the Espionage Education System of its many tax dollars. Nor was it rushed out by a bearded hack, typing fraudulently in the night, posing as a so-called expert. The Secret Agent Field Guide contains a fully vetted 200-proof distillation of street-level espionage expertise, gathered from the streets of New York, London, and ports abroad. This illustrated edition replaces all previous editions. Additional copies may be ordered from the address on the back cover or from your superiors. We hope it serves you well now and in the future, such as the 1970s".