A rare late 18th century Russian silvergilt and niellowork oval snuff box

A rare late 18th century Russian silvergilt and niellowork oval snuff box, decorated with two musicians on the cover within a border of entwined ribbons, against a ground of patterned linear engraving, the sides with figures, masks and architecture, the base with a figure in a landscape, gold thumbpiece, no maker's mark, town mark struck twice, Moscow c.1765, 3.7in (9.4cm) wide, 3oz.