Cover franked with 1929 20c sepia and 30c black AIR issue (SG 472 & 479) tied by SERVICIO AEREO MINATITLAN cds's dated 21 AUG 1931 with large boxed 'PAR AVION POR AVION' marking in blue alongside. Addressed to UK and redirected a number of times to Egypt and twice more in the UK with various transit & arrival markings the latest dated 16 OCT.