Watch List notes:

MONTSERRAT: AE three halfpence (1.59g), ND, KM-1, Vlack-405; Prid-8, "M" countermark on reverse of a French Cayenne copper 2 sous issued locally circa 1780-90, VF, ex Dr. Axel Wahlstedt Collection. This type was known as a "black dog." The name comes from the negative connotations of the word "dog," as they came from debased silver coins, and the dark color of those same debased coins. "Black dogs" were also at times called "stampes" or "stampees," as they were typically countermarked on the coins of other colonial powers, especially French Cayenne coins worth 2 sous or, equivalently, 24 deniers, stamped to make them British currency.

Estimate: 150-250 USD