KM-4, J-712 variety.
A stunningly beautiful piece, with fresh luster, wild multi-hued toning and a neat design featuring Wihelm II in a hat which would be right at home in a game of Stratego:
Plus this coin is pedigreed to one of the most important collections ever assembled.
How cool is that? Very.
This coin is from the CRO archives and is not currently available for sale.