There are a number of places online that show Preliminary Specification S-23A for the XP-67 aircraft, dated 5 May 1941, but the aircraft's Final Report says that changes were made to its contents for the final release version dated 20 July 1942. I've looked everywhere I can think of with no luck at all. Does anyone have a copy of that 1942 version? It seems strange that the preliminary is so readily available but the authoritative specifications are nowhere to be found.