Russia
R.S.F.S.R. silver Proof 50 Kopecks 1922 AГ PR66 NGC, Leningrad mint, KM-Y83. Obv. National arms. Rev. "50" in star with date below. Boldly struck, with near-flawless surfaces and a touch of light reddish patina. Only a single piece has been certified finer by NGC.
Estimate: 4000-5000 USD