Watch List notes:

Potosi, Bolivia, cob 8 reales, 1666E, "666" date between pillars. S-P37a; KM-21. 23.90 grams. Full pillars-and-waves with clear 666 date despite flatness and surface corrosion (also very dark toning) as from unspecified salvage (probably Piedmont), otherwise AVF, with off-center cross. (Estimate: $200 - 300)