Russia
Nicholas I Proof Pattern Denga (1/2 Kopeck) 1840 CПБ, St. Petersburg mint, Bitkin-935, Brekke-38, PR65 NGC. Obv. Crowned monogram. Rev. Date and value. Boldly struck with reddish-brown patina and hints of original golden color. The surfaces are fully mirrored and display only a few tiny, barely noticeable, spots. No examples have been certified finer by NGC.
Estimate: 2000-2500 USD