Now We Have Proof !
Been to some war materiel sites in Alabama with a friend from there avidly interested in its history.
Been to a Naval Ordinance Production site near Talladega where they produced Naval Ship Ordinance during WWII....
Big, big, bid damned shells. Tons each seems like. Women worked that plant.
Heavy, heavy concrete bunkers, copper lined (no sparks), segmented assembly, heavy work. They did okay.