War surplus 10 years after the war? I hae me doubts.
I don't know, but I bet it's because Henry got a good deal from the supplier!
I think Will N nailed it
Remember that engines were sprayed in alkyd enamel. Initially, the only other enamel paints used were black until the plants started painting wheels in colors other than black in 1930. Bodies were painted in nitrocellulose lacquer.