Fine Swiss 18K gold Twenty Dollar coin watch Circa 1980

Gold coin watch by Vacheron Constantin
–
A Swiss 18-carat yellow gold,manual-winding, Swiss keyless watch, circa 1980, set into a 1904 20 dollars U.S. coin (20K gold).
Lever manual mechanical movement stamped with Geneva seal, 17 jewels. Gold dial with painted stick indexes, baton numerals, and blued steel hands. Circular case, snap-on back, all hinged within a United States of America Twenty Dollar coin, the front with the Lady of Liberty and dated 1904, the bald eagle to the reverse, opened by pressing the thumbpiece in the milled band. Dial signed, case and movement signed and numbered—bag watch embedded in a 20K and 18K gold piece.
–
Diameter: 36 mm
–
Weight: 38 g
–
Signed: Vacheron Constantin Genève Swiss