Second Known?

CNG 106, Lot: 603. Estimate $500. Sold for $7200. This amount does not include the buyer’s fee.

BITHYNIA, Nicaea. Britannicus. AD 41-55. Æ (23mm, 6.86 g, 12h). C. Cadius Rufus, proconsul. Struck circa AD 47-48. Bareheaded and draped bust right / Γ ΚAΔIO[C]/POYΦO[C] AN/ΘYΠATOC in three lines above NIKAIA monogram; all within wreath. RG 35 = RPC I 2041.1. VF, green patina. Only one cited in RPC, none listed in supplements or in CoinArchives. Apparently the second and finest known, and the only in private hands (the other in the Numismatic Museum, Athens).