Swiss silver open faced lever watch with calendar Circa 1980

Silver dodecahedral calendar watch by IWC
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A large Swiss silver open faced lever pocket watch with calendar, circa 1980. Lever movement, keyless winding, jewelled. Silvered dial with central indication of time, Roman hours and Arabic minutes, a ring with zodiac signs, outer calendar. Plain dodecahedral case. Dial signed, case and movement signed and numbered.
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Diameter: 57.5 mm
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Signed: International Watch Co Schaffhausen