China - U.S. Offices, 1871-74 U.S. Postal Agency Shanghai covers. 4 covers from Shanghai to U.S. (2 with original letters), franked with 10¢ Banknotes, one Consulate General postmark, two with original enclosure, condition mixed, almost Fine. Scott No. 150, 161  Estimate $400 - 500. $0 (Image)