The penalty for counterfeiting and forgery of banknotes (imprisonment at least two many years) appeared to the higher proper corner with the reverse of all 3rd collection banknotes. Note this is the submit-1970 variant, that includes "Freiheitsstrafe" in lieu of "Zuchthaus". Common security features at the time were guilloches, a https://chex975weo3.shivawiki.com/user