Cover franked with 1944 15c mauve and 1946 1c blue on front and 1938 10c orange and 1946 5c carmine on reverse (SG 933, 947, 897 & 949) tied by 'Wavy Lines' cancels with fine CERTIFICADOS CHALCHUAPA cds & boxed CHALCHUAPA registration marking on front. Sent airmail to MEXICO with small 'VIA AEREA' airplane handstamp and MEXICO arrival marks on reverse.