20 Kopecks 1843, St. Petersburg Mint, SPB ACh. 4.16 g. Proof. Bitkin 326 (R3). Excessively rare. 15 roubles according to Petrov. 30 roubles according to Ilyin. NGC PF65. Beautiful condition with magnificent patina.

From the Soedermann Collection, auction SINCONA 24, Zurich, October 2015, lot 679 (price realized: CHF 48,000).
From the "Russian Coins of 19th and 20th Century. Collection of Duplicates from Russian Museums", auction Adolph Hess 204, Lucerne, February 1931, lot 1037.