Swiss gold skeletonized split second chronograph Circa 1980

Gold keyless lever pocket watch
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A large Swiss 18 carat yellow gold skeletonized keyless pocket watch made by Omega in Bienne, circa 1980. A Louis Brandt Olympic limited edition, No. 58. This watch has three horological complications: tenth of a second chronograph activated by a single round push piece on the winding crown, split seconds activated by the olive shaped push piece in the case band at 11:30 and a half instantaneous 30 minute counter at 12 o’clock. The case is smooth and the skeletonized dial features an outer minute track with fifth of a second divisions and Arabic five minute numerals, a 30 minute counter, subsidiary seconds at 6 o’clock and fine hands. Fully skeletonized and engraved gilded brass movement with a going barrel, 23 jewels, a straight line lever escapement, monometallic balance and Breguet hairspring, an index regulator with a swan neck spring and micrometric screw, the chronograph and split seconds work on the top plate. Signature on the dial, case and movement.
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Diameter: 69 mm
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Signed: Ω Omega Bienne
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Accompanied by the original fitted presentation box and outer protective case.
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The Olympic skeleton chronograph was made in small numbers in 1980 to celebrate 50 years of Omega’s association with Olympic timekeeping in 1982, since the 1932 Games of Los Angeles. Some sources mention that this model was produced in 63 examples.
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This model was available in three different case styles:
– polished, reference BA 143.6716
– partially chased, reference BA 143.6717
– entirely chased, reference BA 143.6718
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In the early 1980s, these watches were used in Omega advertising with the caption: Omega celebrates 50 years of Olympic timekeeping with a creation symbolising 134 years in the craft of watchmaking. This model is illustrated and described in Omega – A Journey Through Time, by Marco Richon, p. 569.