San Marino. Michel 174 cover, 1931 Air mail 10 L blue on registered card cancelled REPUBBLICA DI SAN MARINO POSTA 14 APR. 932 AEREA, to Recife, Brazil. Arrival canc. Pernambuco 20 IV. 32. Brown cachet "LUFTSCHIFF GRAF ZEPPELIN 3. SÜDAMERIKA FAHRT 1932". Rare card!