Watch List notes:

BRITISH COINS, Charles I, Silver Halfcrown, 1643, Oxford mint (1642-1646), king on horseback left, upright sword, flowing sash, plain groundline below, Oxford plume in field, legend and borders surrounding with pellet and colon stops in legend both sides, initial mark plume (1642-1646) both sides, rev declaration in two straight lines, value and three Oxford plumes above, date below, 14.37g (N 2415; S 2955). Light scratch in obverse legend near front raised horse hoof, weakly struck in parts, otherwise very fine for issue, lightly toned.
from the David Sellwood collection

Estimate: £600-800