These are original new old stock tiny notebooks from the 1930s / 1940s with a "Pst! Feind hört mit" (Shh! The enemy listens with you) stamp added. These came form an old warehouse cleanout in Germany. They show some storage wear / age-related discoloration. Staples may have rust. Price is for one.
The notebooks themselves are original but the stamp on the back is recently added.