Registered cover franked with 1934 17c red, blue and grey and 36c scarlet, yellow & black 'Closure of the 7th Pan American Conference' TRIANGULAR issue (SG 714/715) tied by 'CORREOS - URUGUAY SERVICIO POSTAL AEREO CLAUSURA VII CONF. I. AMERICANA PRO-PAZ-PARAGUAY-BOLIVIA 1 - ENERO - 1934' cachet in black with printed MONTEVIDEO registration label tied by MONTEVIDEO cds dated 1 JAN 1934 alongside. Flown on the 'Montevideo - Maldonado - Lavalleja - Rocha - Treinta y Tres - Cerro Largo' first flight. Addressed to CERRO LARGO with MELO arrival cds on reverse and 'Desconocido Inconnu' label on front. A very scarce flight. (Muller #67, rated 3500pts)