Cover franked with 1927 1p 50c red brown and 1929 2p 85c on 5c dull purple AIR 'Surcharge' issue (SG 305 & 345) tied by SCIO AEREO POSTAL PARAGUAY cds's dated 1 JAN 1929. Flown on the Inaugural ASUNCION - BUENOS AIRES flight (on the 2nd of Jan) by 'Vachet' with boxed 'CORREO AEREO REP. DEL. PARAGUAY' first flight cachet. Addressed to BUENOS AIRES with arrival cds on reverse dated 2 JAN 1929. (Muller #3, rated 3000pts)