Notgeld was really used in Germany in 1923. The article, dated October 1923, gives a truthful description of the value of money during a hyperinflation. There's just one anachronism: in 1923 the World War 1 wasn't referred to as such, as there hadn't been a second yet.
Of course all the accompanying examples of banknotes were created by Kahn & Selesnick. Their engagement with the environment is demonstrated on the 10000000. In the text on the left oil production is said to set the world on fire, and on the right the Shell company is named 3 times. Translated it reads: "Petroleum is the name of our homeland. For that we make holes in our skin: SHELL, SHELL, SHELL".