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. Some have rounded edges and some do not. Price is for one.
The notebooks themselves are original but the stamp on the back is recently added.