U.S. Postal Agency, Shanghai, Apr 27, 94. Duplex postmark tying 1893, 5¢ Columbian on missionary cover to West Newbury, Mass., with North China College corner card originating in Peking, San Francisco, Cal. transit and receiving backstamps, Very Fine, a scarce Columbian issue usage from Shanghai. Scott No. 234  Estimate $600 - 800. $0 (Image)