Watch List notes:

SWEDEN: Adolf Frederick, 1751-1771, AE ½ daler silvermynt (386g), 1755, KM-PM80, Opitz p.255 (plate example), 116 x 92mm, "plate money" issue, some light scratches, a very nice example, EF, ex Charles Opitz Collection. From 1624, daler were issued in copper as well as silver. Because of the low value of copper, large plate money (plåtmynt) was issued. These were rectangular pieces of copper weighing, in some cases, up to several kilograms. They circulated until 1776. As silver became scarce, the silver daler rose in value relative to the copper daler, with the exchange rate between the two eventually being set at a ratio of 3 to 1. Denominations in copper money were marked K.M. or KMT, with S.M. or SMT denoting silver money. The cumbersome size and weight of plate money eventually prompted Sweden to become the first country in Europe to issue banknotes.

Estimate: 300-500 USD