Gold English Lever with Decorative Gold Dial

An early 19^th Century English lever with decorative four colour gold dial in a gold open face case.  Full plate gilt keywind fusee movement, gilt dust cover.  Harrison's maintaining power.  Plain cock inscribed "Detachd" on the table and "Lever" on the foot.  Diamond endstone, blue steel Bosley regulator.   Plain three arm gold balance, blue steel spiral hairspring.  English table roller lever escapement.  Fine decorative gold dial, matted ground,  three colour applied gold decoration to the centre and edge, applied polished gold Roman numerals, blue steel hands.   Decorative 18 carat gold open face case, chased and engraved middle, bezels, pendant and bow.  Faded engine turned back with vacant circular cartouche, maker's mark "SB" in a rectangle.