According to the referee, the proof version of this coin does not actually exist, contrary to what Krause says. The proof coins were struck with a purity of .925 rather than .500 (KM#734a rather than KM#734), so the proof version his its own page: https://en.numista.com/catalogue/pieces41063.html
Status changed to Rejected(Sulfur, 6 2月 2020, 17:29)