Special cover commemorating the Aviation Conference, sent by airmail from Lima to New York on 16/SE/1937, franked with 1.50S. On back it bears an interesting mark: "Expedida por Avión - Solo hasta Panamá - por insuficiencia de franqueo - Pesa 10 gmos.-Tiene S/1.45", and with several postal marks, eventually returned to sender on 25/NO! (Image)

Airmail cover sent (circa 1940) from IQUITOS to Manaos franked with 1.75S., very attractive! (Image)