Swiss gold minute repeating American calendar Circa 1977

Gold complicated lever watch by Patek Philippe
–
A fine and rare Swiss 18 carat gold open faced minute repeating perpetual calendar with American (digital) calendar display and moon phases, circa 1977. Retailed by Chronometer Beyer, Zürich. Sold on 7 August 1981. Lever movement, 29 jewels. Silvered dial with raised hour markers and minute divisions. Plain case made by Gerlach. Case, dial and movement signed, case and movement numbered. Comes with the original presentation box and an Extract from the Archives confirming the production of this watch in 1977.
–
Diameter: 51 mm
–
Signed: Patek Philippe Genève Swiss
–
One can identify the very crisp case lines that are very reminiscent of the perpetual calendar automatic wristwatch. Introduced in 1965 and was available for the next 40 years, it is estimated that there was as little as only 80 pieces made.