Watch List notes:

Mexico City, Mexico, cob 8 reales, 1680 L, rare. S-M21; KM-46; Cal-641. 16.78 grams. Thin from saltwater corrosion yet with a clear mintmark, assayer initial, and final digit in the date plus some shield and cross detail. With original (generic) certificate from the salvors. From: Joanna, sunk in 1682 off South Africa
($150-225)