Principality of Warsaw, Frederick August I (1807-1815), lot of 5 groszy 1811-1812 I.B., mint Warsaw
1811 I.B., 1811 I.S., 1812 I.B. (punched on 1/24 of the Prussian thaler R2) - all sound, fully legible coins with patina
coin silver, total weight 5.50 grams, diameters 20-21 mm