1960s Omega "Seamaster 120" Automatic Date Black dial with Original Bracelet

Manufactured in the mid-1960s, this is an Omega “Seamaster 120” Automatic Date with a black dial, complete with its rare original bracelet.
It is a diver’s watch equipped with a rotating bezel and a C-line case design, which it shares with the Constellation series.
This model was offered in various configurations with the same design, including 31mm and 37mm case sizes, and both automatic and manual-winding movements. The 31mm version features a unique compactness, and the automatic movement adds a sense of weight and presence—resulting in a distinctive and appealing size and feel.
It comes with a valuable original bracelet from the period (reference 5684FF537, stamped 2/67, fits wrist sizes up to 18cm).
The watch is powered by the automatic Caliber 681 movement, which features a quick-set date function (the date advances by moving the hands back and forth between 8 PM and midnight).