MEXICO. 4 Reales, 1844-Pi AM. San Luis Potosi Mint. NGC AU-55.KM-375.8. Nicely detailed on the obverse with just a slight weakness on the reverse center. The unbroken smoothness of dark earthy toning show the great care that has been taken to preserve this example. Extremely similar overall to an example graded AU-58 that we sold in March 2011 for $600 hammer.Ex: Richard Ponterio Collection.