I would assume that Arnold did work for MF since he was in Chicago and well respected. I would like to see closer pictures of the gun to compare the style and subjects with other guns he did. Arnold did many "stock" scenes, especially on Model 32 Remingtons and Krieghoffs, but this gun does not seem to be a "stock scene". A gun made for the president of MF, outrageous. The Cody letter could shed more light.