A late 18th century three-dimensional memorial brooch

A late 18th century three-dimensional memorial brooch, of upright and long oval form, holding a three-dimensional obelisk decorated with a laurel wreath and a seed pearl urn, on a monumental base inscribed 'WP', under a weeping willow, the domed glazing with further willow fronds of hair also covers a narrow blue enamel border with spot decoration, in a rose metal mount, the concave back engraved 'Will'm Paterson, Ob 8 Apr'l 1791, Æt 41'; length 3.0cm