cover DuPont Smokeless, multicolor pheasant perched on split-rail fence in a hay field design on 1898 DuPont illustrated ad cover, franked with 2c Carmine (267), target cancel, 'Henry Clay Factory, Del.' c.d.s., 'Missent/to Stonington, Conn.' straight line h.s., also incl. same design but for DuPont Sporting Powders on an unused envelope which has an additional multicolor overall text ad on reverse, very fine lot photo ex