English gold lever with 52½ minute carrousel Circa 1900

Gold full hunter lever with carrousel by S. Smith & Son
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Very fine and rare yellow gold hunting-cased keyless-winding English pocket chronometer with patented 52 ½-minute Karrusel (carrousel) regulator, circa 1900-1901.
Gilded brass ¾ plate movement, ebauche by Bahne Bonniksen, going barrel, English lateral lever escapement, cut bimetallic compensated balance with gold and platinum poising screws and blued steel hairspring with a double terminal curve, diamond end-stone, index regulator, mounted on a Bonniksen 52 ½-minute Karrusel (carrousel) carriage. White enamel dial with radial Roman numerals, subsidiary seconds at 6, and original blued steel spade hands. Round-shaped 18K yellow gold case, cover and case back polished, case numbered 189-255 (by Samuel Smith, London), with London letter date for 1900-1901, cover engraved in taille-douce (fine-cut) with the cypher L R.
Dial, case and movement signed, and  Bonniksen’s mark on the main plate. Accompanied by contemporary fitted box (signed by Barraud & Lunds, Cornhill).
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Diameter: 54 mm
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Signed: Smith & Son 9 Strand, London 189-255
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Overhaul recommended—hairlines on enamel and various types of decoration.