It sounds like the solution was always left as an exercise for the reader in the day-to-day dealings of the group even among the members: "Each participating country was supposed to perform its own decryptions. This is common practice in the intelligence community in order to prevent being fed cooked-up information." and "The cryptanalytical part of the cooperation involved exchanges of algorithms used in various (deliberately weakened) cryptographic devices used by target countries. It was then left up to the Maximator participants themselves to find out how to exploit weaknesses in the algorithms of these devices. Such exploitations are also called ‘solutions’."