While basic in terms of historical information, it's holds its own as useful and game-specific tidbits to spice up your pulp campaigns.
It does well to point out that the "nazis being typical pulp villians" is a modern misconception, for they appeared as such near the end of the pulp era. Still, gives plenty of room for you to create a detailed campaign where your players have a go against these opponents in the pre and early war timeframes.
Used in conjunction with Zeppelin Adventures, you can have lots of hours of fun in a pre-WWII setting where Europe is in the brink of chaos, spies are everywhere and there's nothing a determined pilor/hero can't do to save his paramour, his reputation and the world, all at the same time.
The crunchy bits are the typical high-standard you can expect from Adamant Enetertainment and conforming well to the d20 usual fare. Still, there enough information in there to translate it to any system without having a nightmare pf a time doing so.
This is a nice addition to any pulp enthusiast's rpg collection. I recommend it heartily.
[5 of 5 Stars!]