Watch List notes:

Charles II (1660-1685), 'Plume' Shilling, 1679, second laureate and draped bust right, plume below, rev. four crowned shields cruciform, plume at centre, five strings to harp, obliquely milled edge, 5.69g, 6h (Bull 548 [R3]; ESC 1056; Spink 3376), irregular and square cut planchet, historic scuffs above head and a faint crease to flan, otherwise toned, about fine, very rare.
Bull 548 gives 7[?] strings, but on this coin the five strings are clear.
Estimate: £400 - £600