In The Comic Reader #27 (July 1964), George Kashdan is credited with writing the Blackhawk fillers. Info per Nick Caputo.
Letters from Robert Lieberman, Steven Sawicki, Mike Tannery, Craig O'Brien, Kraig Harris, Leon Kurtzweil, Tiger Thompson, Ben Sokolowski, Dave Scott, Philip Galafaro, Robert R. Waters, Mike Tachia, Joel Keller, David Pomerantz, Scott Shincarick, Genny Hays, David Gray, Terry Melvin.