Watch List notes:

Mexico City, Mexico, cob 8 reales, 1637/6P, very rare, ex-Concepcion (1641), ex-Rudman. S-M19; KM-unl (45 for type). 24.02 grams. Broad and somewhat barrel-shaped flan with much flatness but with clean, matte surfaces, the date full and clear (first we have seen with 7/6), as is the oMP, no corrosion (still impossible to grade), with small patches of dark orange encrustation on part of edge. From the Concepcion (1641), and pedigreed to the Isaac Rudman collection.
($500-1000)