Watch List notes:

Russia, Nicholas II, proof rouble, 1910ЗБ, bare head l., rev. crowned double-headed eagle (KM.Y59.3; Bit.64[R]), in plastic holder, graded by PCGS as Proof 66, a superb gem proof * ex Mark Teller, 1998 A rare date in any condition, as a proof it is exceedingly rare. This superb gem proof is the finest graded by PCGS and NGC – NGC has graded one example at PF65, two at PF63 and one at PF62. This is an outstanding example of a 1910 proof rouble. It possesses gorgeous scintillating deep reflectivity with beautiful overtones of pink and bluish purple toning on both sides. The surfaces are also absolutely pristine, with an especially smooth cheek on Nicholas's portrait. It is an amazing coin and probably one of the finest known. A choice proof 1910 rouble sold as part of the Sincona collection in October 2013 for US$37,000.

Estimate: £25,000-30,000