Nice contemporary counterfeit of the period. Probably a mercuric silver amalgam wash over a copper or toned brass debased alloy. Unquestionably of the striking period. Too bad the owner thinks its real. First one I have seen of the denomination/type - not that's a big deal as with some countries these CCs don't surface on E-Bay unless by accident or by an astute collector/dealer. I would pay $40 for this piece for my collection. I am finding most Ag or Au washes use mercury to create this Ag/Hg type amalgam surface which after heat/annealing burns off most of the mercury on the surface leaving a nice silver film as in the case of this piece on the obverse (more than the reverse) but XRF analysis always discovers remnants of Hg on the surface "sometimes" at levels of 1-10% but mostly in levels of 0.1 - 1.0%. This type of mercury/metallic compound is not toxic to the touch as these Ag/Hg amalgams are inert.
John Lorenzo
United States