Watch List notes:

Potosi, Bolivia, cob 1/2 real, Philip II, assayer B (5th period) to left, mintmark P to right, borders of x's, with monogram side punched over 1/4R design, unique. S-P14; KM-2.3. 1.24 grams. Corroded and toned (from salvage, VF otherwise) but with full inner details and much legend, the borders of x's rather prominent and the assayer full and bold, but most interesting feature is a faint but certain castle under the monogram, along with the shield-shaped outline (bold) that contained the castle on the original 1/4R design.
($150-300)