Serviced Vintage 1966 JAPAN SEIKO SEIKOMATIC WEEKDATER 6206-8100 26J Automatic.

Serviced Vintage 1966 JAPAN SEIKO SEIKOMATIC WEEKDATER 6206-8100 26Jewels Automatic.

Welcome to my auction!
I am Japanese who live in Tokyo.

Item description

Movement :

• Pet name : SEIKOMATIC WEEKDATER .
• Caliber number : 6206A,B.
• Movement : Automatic.
• Beat rate : 18000bph.
• Year of manufacture start : 1963's.
• Factory : Suwa.

Externals :

• Serial number : 6552394.
• Dial number : JAPAN 6206-8090T AD.
• Glass : Acrylic.
• Case size : About 37mm.
• Lug width : 19mm.
• Band : Wrist size that can be worn is Up to about 200mm.

Condition :

• Used, it runs well.
• Quick set(Day/Date) : Okay.
  Set the day of the week : English only.
  Set of the date : The set at one stage pulling the crown.
  Set of the week : Iteration the hour hand at 9:00 and 12:00.
• The day difference time of an used watch is about +-1 minute / day.
• Overhaul service in May 2026.
  The movement has been cleaned and oiled, so it works fine.

Key Features

The Mid-60s Standard of Executive Refinement (1966): In **1966**, the **Seiko Seikomatic Weekdater** stood as the quintessential status symbol for Japan's rapidly ascending corporate leaders and white-collar elite. The reference **6206-8100** was produced by the **Suwa Seikosha** factory during a landmark era of unprecedented national economic growth. It was specifically designed to provide the ""New Executive"" with a flawless blend of automatic luxury and professional utility, representing the pinnacle of domestic mechanical pride and mid-century design.

The Sophisticated 26-Jewel Caliber 6206 Heart: This watch is powered by the **26-jewel Caliber 6206**, a high-grade automatic movement operating at **18,000 vibrations per hour (vph)**. In **1966**, a **26-jewel specification** was a clear mark of premium engineering, utilizing extra synthetic rubies to ensure an ultra-low friction environment for the complex gear and calendar trains. This caliber features the legendary **Magic Lever** winding system for supreme automatic efficiency, celebrated for its robust architecture that has endured for over half a century.

Architectural ""8100"" Refined-Lug Case Design: The reference **6206-8100** is renowned for its elegant, streamlined case geometry. Distinct from other variations, the 8100 profile features beautifully proportioned, clean lugs and a polished bezel that adheres seamlessly to the early principles of the **""Seiko Style.""** A signature trait is the **recessed crown at the 4 o'clock position**, which visually manifested that the watch was so efficiently self-winding that manual intervention was obsolete, maintaining a sleek silhouette under a bespoke dress cuff.

Masterful ""Weekdater"" Dial Symmetry: The dial of the **6206-8100** is a study in clinical elegance, featuring a radiant sunburst silver finish and **hand-applied, multifaceted baton indices**. A signature of this elite lineage is the beautifully balanced dual-calendar layout: the date sits at 3 o'clock, while the **""full window"" day-of-the-week disk is positioned independently at 6 o'clock**. Framed in polished steel, this balanced arrangement prioritized instant professional legibility and remains one of Seiko's most recognizable dial designs.

A Landmark of Suwa's Automatic Heritage: Produced in **1966**, the 6206-8100 remains a highly coveted reference for vintage collectors of the 62-series. It represents the crucial historical bridge between early luxury Seikomatics and the legendary 62GS (the first-ever automatic Grand Seiko). It stands as a profound testament to an era when Suwa Seikosha perfected the **""Professional Business Watch,""** creating a nearly indestructible and visually striking masterpiece that remains as dignified and reliable today as it was sixty years ago.

For more information, please look at the pictures.

Notes

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