Below is from the Berkun-Siskin data base for EDU's. It does not state whether its the pre-cancel or not; though it probably is. You can access this data base through Richard Frajola's site:
www.rfralola.com >articles>mercury projects>earliest documented usages of US stamps to 1931. The problem with EDUs is there is not one single source for keeping track of EDUs. There's Berkun-Siskin, Scott, APS, Siegel, the PF and probably other sources. I remember reading that Ken Lawrence had his own data base too. Richard keeps Berkun-Siskin up-to-date as long as new EDU's information is sent to him. He can up-date the file at anytime whereas Scott can only be up-dated annually. Siegel's listing, unless other info. is known would be your answer.
Posted 05/13/2018 2:33 pm
