Offices in China, 1922, 4¢ on 2¢ carmine, two singles, one with natural s.e. at left, tied by "U.S. Pos. Service, Shanghai, China, 1922" duplex postmark on double rate cover to New York City, Nanyang University corner card; cover with some postal ink smudging, otherwise Very Fine, a scarce double rate usage of the provisional overprint issue. Scott No. K18  Estimate $200 - 300. $0 (Image)