Estados Unidos
Automatically generated translation
Yvert 232, 233, 242, Aerial 15A. 1936. 3 cents violet on Postal Stationery from NORFOLK to NORBLAUFEN (SWITZERLAND), with complementary postage of 5 cents, 6 cents, 20 cents and 6 cents air. On the front handwritten notation "Air mail via Hindenburg" and on the back FRANKFURT transit roller. MAGNIFICENT.