AUSTRIA - AUSTRIA Olomouc (Olmütz, bishopric of), Rudolf John of Austria (1819-1831). Half-thaler of convention 1820. Av. RUDOLPH. JOAN. D. G. CAES. A. R. HUN. BOH. PRINC. A. A. Bust of the prelate on the left. Rv. S. R. E TIT. S. PETRI IN MONT. AVR. CARD. ARCHIEP. OLOM. (date). Shield surmounted by the attributes of the prelate, resting on a crowned mantle. KM.492; Silver - 14.01 g - 34.5 mm - 12 h NGC AT 58 (8583598-008). Minimal flats on the high relief on the right, with a few hairlines. The reverse is preserved. Light grey patina on the right side with most of the shine on the reverse. Superb / Superb to Fleur de coin.