Mexico City, Mexico, cob 4 reales, Philip II or III, assayer F below denomination 4 to left, assayer D (no o) below mintmark oM to right (F-D), very rare. 6.47 grams. Darkly toned and moderately corroded but with clear full shield and cross, bold oM mintmark above big space (no o) above D. Recovered from: "Rill Cove wreck," sunk ca. 1618 off Cornwall, England (Estimate: $150 - 225)