Watch List notes:

Potosi, Bolivia, cob 8 reales, (16)21(?)T, mintmark backwards P over P, quadrants of cross transposed, encapsulated NGC VF 25. S-P21; KM-10. 27 grams. Bottom of ZI of date visible (with room for possible II to right, hence could be a 1623, despite the certainness of the date on the tag), choice full cross-and-tressure and shield (slightly off-center), full and curious "q/P" mintmark, dark orange sediment on fields. (Estimate: $250 - 375)