China - U.S. Offices, 1897 China and Japan mixed franking. China 10¢ dark green (Scott #91) and 1888 Japan 10s brown orange (#79) tied to 1898 cover to U.S.; China issue tied by large blue double circle cancel (probably Chefoo) and Japan issue tied by red-brown NINSEN I.J.P.O. cancel; postmarks on back are Yokohama, San Francisco and Wooster, Ohio; original letter from Tungchow enclosed, fresh and F.-V.F. Estimate  $600 - 800. $0 (Image)