The penalty for counterfeiting and forgery of banknotes (imprisonment at least two decades) appeared on the upper correct corner in the reverse of all 3rd collection banknotes. Note this is the post-1970 variant, showcasing "Freiheitsstrafe" instead of "Zuchthaus". Typical security features at the time have been guilloches, a multi-level head https://zachp641mve0.blogpayz.com/profile