An early 19th century gold, diamond and enamel cylinder pocketwatch

An early 19th century gold, diamond and enamel cylinder pocketwatch
The white enamel dial with Arabic numerals and outer minutes, the gilt cylinder movement with pierced foliate bridge cock and triple arm balance wheel, the case bezel set with old-brilliant-cut diamonds, the reverse of dark blue guilloché enamel with applied rose-cut diamond-set monogram A M, within a brilliant-cut diamond border, the bow set with rose-cut diamonds with brilliant-cut diamond single stone terminal, dial and movement signed Adamson Millenet, circa 1820, case diameter 36mm