MEXICO. Mint Error -- Off Metal Strike, Struck on Aluminum-Bronze Planchet -- 50 Centavos, 2017-Mo. Mexico City Mint. PCGS MS-64.
KM-936. Normally one encounters this type as a stainless steel issue, but this example rather curiously seems to be struck on an aluminum-bronze planchet cut down to fit a 50 Centavos strike.
Estimate: $150 - $300