Watch List notes:

BRITISH COINS, Charles I, Silver Pattern Half-Groat, by Nicholas Briot, bare head bust in ruff right, breaking bottom linear circle surrounding, initial mark rhombus, rev crowned pair of interlinked C's, .B. below, linear circle and legend surrounding, 1.41g (Brooker 1255; N 2687; S 2856A). Good very fine, toned and scarce.
purchased from CNG, c.2002

Estimate: £100-150