15c vermilion with 'CORREO AEREO OFICIAL' overprint, a fine mint copy with variety OVERPRINT DOUBLE. Only one sheet of 100 was printed. Very scarce. Expertised 'Sanabria' on reverse. (SG O688b, Maxwell #OA4e)
15c vermilion with 'CORREO AEREO OFICIAL' overprint, a fine mint copy with variety OVERPRINT DOUBLE. Only one sheet of 100 was printed. Very scarce. Expertised 'Sanabria' on reverse. (SG O688b, Maxwell #OA4e)