Well, if you need to know "Dr. Bob". J/k! I have bought pedals in the past that people have said the adapter was purchased when they bought the pedal new in 1981 or 1984. Also, The NOS RV-2 that I am trying to get comes with adapter in the box with it. I'm just wondering how to tell if they are indeed original. I know a few that I have do have a 4 digit number stamped on them right next to the words "DATE CODE". Hoped those might help?