Airmail cover from Philadelphia, Chaco, Paraguay franked with 1939 pair 100p emerald green, 1940 10p magenta and 1942 7p chestnut (SG 526, 540 & 571) tied by SCIO AEREO POSTAL PARAGUAY cds's dated 21 ABR 1943. Addressed to USA and censored in transit in Trinidad with printed 'P.C.90 OPENED BY EXAMINER 4909' censor strip at right with 'IE/-' handstamp in purple.