Watch List notes:

Alexander I (1801-1825), Novodel Polushka [¼- Kopek], 1806-KM, Kolyvan, crowned double-headed eagle, rev. value and date, edge obliquely grained, 1h (Brekke 17; Diakov -; Bitkin 471), bluish tone overlying brilliant patinated surfaces, much as struck, extremely rare, in NGC holder, graded MS64 BN (Cert. 4079520-003)

provenance
New York Sale XXIX, 5 January 2012, lot 2151