Cover with typed 'E. Abal, Mercedes 1051 Montevideo' return address at top left franked with single 1919 4c grey & orange (SG 352) tied by superb strike of large ESTAFETA AMBULANTE 33 cds dated 26 AGO 1920 of the Montevideo - Mercedes line. Addressed to MAR DEL PLATA, ARGENTINA with arrival cds on reverse.