cover 4c Offices in China (K2), twelve stamps incl. blocks of four and six, all tied by 'U.S. Postal Agency Shanghai, China' double oval cancels on back of 1922 linen-lined registered cover (9¼x4¼") to N.Y., cover faults, one stamp in the block of four is faulty, nearly all others are fine-very fine, Scott retail as used stamps $450.00+