Mexico City mint, KM155, Onza-752. A well-detailed coin with limited actual wear, cleaned long ago and with some scratches near the legends of the obverse defining the grade. A superb example of this very rare date, absent in both Gerber and Eliasberg and rated as such in the Onza reference work. The Rudman example of this rarity was an impaired, albeit well defined coin. Extremely rare in this handsome quality, with no examples certified higher in the NGC census and no true Mint State coins known to us.