I'm not really sure, not familiar with uniforms of Neapolean time. But this looks more modern, like DeGauld wore during WWII. The wording on the painting (this is a published picture by Parisian Art, Inc., New York, N. Y.) Ferdinand Foch, Marshall of France, Generalissimo Allied Armies. "Our Forces will never again loose the initiative". On the painting is the name C. W. Svensson with a 19 then circle with c and then another 19. Probably is copywrite.