Registered First Flight cover franked with 1931 'Primer Vuelo Postal BARRIOS MIAMI 1931' overprint issue set of three and 1927 1c olive green Tax issue (SG 251, 264/266 & 223) on front and pair 1930 2c black & mauve on reverse all tied by large boxed 'VUELO INAUGURAL DE LA RUTA BARRIOS - MIAMI 5 DICIEMBRE 1931' cachets in purple with boxed registration marking and GUATEMALA CITY cds dated 5 DIC 1931 on front. Flown on the PUERTO BARRIOS - MIAMI FAM 5 first flight with lovely blue 'Nurse & Quetzals' RED CROSS cinderella label inscribed 'AYUDE UD A LA CRUZ ROJA GUATEMALTECA' and red blue & white 'Arrow' airmail label tied with stamps on reverse. Addressed to MIAMI with transit and arrival cds's on reverse. (Muller #50 rated 1500pts, Goodman #AM32b)