secondhand Jaeger-LeCoultre Master-Quartz Ref. 23303-42 wristwatch, blue dial

Used • Unisex • Color: Blue, Silver

#vintage • #rare • #jaeger • #swiss • #jaegerlecoultre

Jaeger-LeCoultre Master-Quartz Ref. 23303-42

Production Details
• Manufacturer: Jaeger-LeCoultre (Le Sentier, Switzerland)
• Original Production: Approximately 1972–1974
• Factory Service Upgrade: Early 1990s (Official JLC Service)

General History
The Master-Quartz was introduced at the peak of the Quartz crisis in the 1970s, as a result of a collaboration between Jaeger-LeCoultre and Girard-Perregaux. The initial models featured the revolutionary GP Caliber 352 movement, which established the international frequency of 32.768\text{ Hz} that is still used today. With its characteristic geometric case from the 70s and the iconic observatory pattern with the diamond on the case back, it stands as a milestone in the history of Swiss watchmaking.

History & Uniqueness of This Watch
This particular piece has a unique and documented history:
• Original Form: Manufactured in the early '70s with the GP 352 movement.
• JLC Factory Upgrade: In the early '90s, when the original movement failed and was no longer available, the owner turned to the official service of Jaeger-LeCoultre. JLC replaced the movement with a high-quality Swiss Quartz movement ETA (7 jewels), installing a special adjustment ring and the gold plate with the JL logo on the blue dial.
• Authentic Accessories: During the same service, the watch was equipped with a genuine JLC leather strap and a steel buckle with the JL emblem.

Technical Specifications
• Case: Stainless steel (~38mm) in excellent condition, with sharp edges and preserved brushed/polished surfaces.
• Dial: Deep blue dial with geometric outer scale and strong, authentic patina.
• Movement: Swiss Quartz with JLC stamp, fully functional with a new battery.
• Case Back: Screw-down steel case back with engravings "MASTER-QUARTZ", "32768 Hz", Ref. 23303-42, and internal stamp LeCoultre Co.
• Crown & Strap: Authentic JL crown, genuine black leather strap JLC with white stitching and the steel JL buckle.

Condition & Value Assessment
• Condition: 100% functional. The case is in excellent preservation, while the dial has acquired a unique vintage patina.