My family has four tickets from the late 1970's that still have one day left on each ticket. They were for the MK and each day we entered they were stamped. Are these tickets good forever like some of the admission passes now or did they have an expiration date? Does anyone know? Would they be worth more to keep unused as a collectible? You guys are a wealth of knowledge so maybe someone will know. This is my first time to post a thread-hope it is in the right place. If not I apologize.