Watch List notes:

BRITISH COINS, Charles I, Nicolas Briot's Coinage (1631-1639), Silver Halfcrown, Second Milled Issue (1638-9), king on horseback left with raised sword and flowing sash, rough ground below, smaller lettering with FR for FRAN, initial mark sideways anchor and B (1638-1639) both sides, rev crowned quartered shield of arms, crowned C and crowned R either side, 14.87g (Brooker 724; N 2304; S 2858). Light surface marks and flan just a little convex, good fine, toned.
from the David Sellwood collection

Estimate: £400-500