Lot
664 
American Postal Machine C., U.S. Postal Agency Shanghai, Mar 31, 1906., Flag cancel (type Q14(1)) ties 1¢ blue green (300), corner tear at upper right, on Chinese Imperial Post postal card to San Francisco, some letters light or not visible and partially overstruck by Seattle machine cancel, F.-V.F., known use of about one week in late March and early April of 1906. One of the most sought after of all flag cancels. Estimate $1,000 - 1,500.