1857/60 - USA: 1 cent blue, III type, 10 cents green, 12 cents black, pair, on cover from "GOWANDA 17 JAN N.Y." 1860 to Schnottwil (Switzerland). The cover has been forwarded according to the postal agreement "Prussian Closed Mail" through New York-Aquisgrana. Superb and rare destination Enzo Diena certificate (Yvert Nn. 9+13+14 - € 940++)
