English gold enamel watch for the Ottoman market Circa 1770

Gold pair cased repeating pocket watch by Francis Perigal
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A fine English 18K gold and enamel pair-cased verge quarter repeating pocket watch made for the Islamic market, circa 1770.
Gilded brass and partly blued steel movement, signed (on back plate): Fras Perigal / London, numbered 17389. White, enamel dial with radial Islamic numerals, outer minute track, Islamic five-minute numerals, silver hands set with diamonds, and signed: Perigal / Royal / Exchange / London [Francis Perigal, British, active 1741–67, or Francis Perigal Jr., British, active 1778–1809]. The outer case and inner case: partly enamelled gold. Outer case: set with diamonds and case maker’s mark: gh [possibly George Harrison, British, active beginning 1760, or Gyles Hooper, British, active beginning 1773]. Signed on the back plate of movement: Fras Perigal/ LONDON and numbered 17389.
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Diameter: 40 mm
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Signed: Perigal Royal Exchange London
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There are five Perigals listed in the eighteenth-century records of the London Clockmakers’ Company. This watch may have been made by the founder of the family, Francis Perigal (active 1741–70), who had a shop in the Royal Exchange, or by his son, also named Francis (active 1748–75). In the second half of the eighteenth century, English watchmakers exported many watches for use in Arabic-speaking territories. However, the numerals on the dials were not exactly those used in Arabic arithmetic but were adaptations made by European clockmakers.