Watch List notes:

COMMEMORATIVE MEDALS, British Historical Medals, Queen Mary, complimentary Bronze Medal, c.1689, by Martin Brunner, crowned and draped bust left within a border of roses and acanthus leaves, a wider border around with lightly etched petals and a roped edge, 78mm (cf MI pl LXXV, 3). Very fine and extremely rare.
Helen Farquhar illustrates a similar piece (present whereabouts unknown), stated to be in silver-gilt, in "Portraiture of our Stuart Monarchs on their Coins and Medals", BNJ vol VII, 1911, p.268, which seems to be the only published record of the medal.

Estimate: £150-250