Flag Helmet

As a lad of fourteen or so, on a trip to San Francisco I bought this helmet ($18.00). It was described as a First Army "parade helmet" probably painted by some artist working outside of an Army base in the 1920's.
I've since discovered that the First Army, whose shoulder insignia was the big "A" pictured, was formed in Aug. of 1918 and disbanded in April of 1919 in France. It was reformed just prior to WW2 but I don't think my helmet dates from then. Having discovered that many painted helmets were done in Europe during the post-war occupation, and since the unit remained in France after the armistice, it stands to reason that the painting was done there. Any insights that can be offered would be appreciated.
I'm also working on the assumtion that the lightning bolts coming out of the circle painted over the central screw designate the 78th ID, "The Lightning Division".