Pocket watch: exquisite English gold/enamel pocket watch with early lever escapement, 'mourning case' with memento, surrounded by Oriental pearls and diamonds, Robert Preston London No.493, ca. 1790: Ca. Ø48mm, ca. 97g, top quality English case, London gold Hallmark and master's mark IN, very rare case decoration, both sides set with large rose cut diamonds, back with blue engine turned enamel, on top the glazed middle part containing a lock of hair, surrounded by small Oriental pearls and a wreath, highly interesting, very early English lever movement, similar to the so-called Massey escapement, exceptionally large diamond endstone, elaborately engraved plate, signed and numbered, very well preserved enamel dial and probably original gold arrow hands, in working order and in excellent condition. The watch is a masterpiece of English watchmaking and combines a highly interesting movement with a top quality case. Particularly interesting is the use of the rare early lever escapement, which is extremely rarely found in enamel cases.