Registered cover franked with 1924 10c orange and 20c green and 1930 40c deep blue AIR issue (SG 755/756 & 778) tied by CORREO AEREO EL SALVADOR 'Airplane' cancels with SAN SALVADOR cds dated DIC 10 1930, 'Correo Aereo' FLAG marking and boxed registration marking alongside. Addressed to UK with transit mark on reverse.