Vintage 1964 JAPAN SEIKO SPORTSMATIC5 DX 427990 23Jewels Automatic.

Vintage 1964 JAPAN SEIKO SPORTSMATIC5 DX 427990 23Jewels Automatic.

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

Item description

Movement :

• Pet name : SPORTSMATIC5 DX .
• Caliber number : 7606A.
• Movement : Automatic.
• Beat rate : 18000bph.
• Year of manufacture start : 1964's.
• Factory : Kameido.

Externals :

• Serial number : 4803925.
• Dial number : MADE IN JAPAN 42 799RO.
• Glass : Acrylic.
• Case size : About 37mm.
• Lug width : 19mm.
• Band : New Leather Strap.

Condition :

• Used, it runs well.
• Quick set(Day/Date) : Okay.
  Set the day of the week : English only.
  Set of the date: Press the button near the 3:00 position.
  Set of the days of the week : Turn the hour hand for 24 hours to set it.
• The day difference time of an used watch is about +-1 minute / day.
• For practical, everyday use, it would be advisable to have the movement cleaned and oiled.

Key Features

The Dawn of the ""Deluxe"" Era (1964): In **1964**, the year of the Tokyo Olympics, the **Seiko Sportsmatic 5 DX** represented the first premium evolution of the revolutionary ""Seiko 5"" concept. The reference **427990** was produced by the **Suwa Seikosha** factory during a landmark year for Japan. It arrived as a high-spec ""Deluxe"" version, elevating the brand from a reliable utility watch to a sophisticated status symbol for the modern, Olympic-era professional.

The High-Grade 23-Jewel Automatic Heart: This watch is powered by a **23-jewel automatic movement** operating at **18,000 vibrations per hour (vph)**. In **1964**, the **23-jewel specification** was an elite count for the Sportsmatic line, utilizing additional synthetic rubies to minimize friction in the calendar and winding systems. It featured the legendary **""Magic Lever""** winding mechanism, which ensured maximum efficiency, signaling to the wearer that manual winding was a thing of the past.

Architectural ""427990"" Case and Recessed Crown: The reference **427990** features a robust, circular case with sharp, mirror-polished lugs. A defining trait of the Suwa factory is the **crown recessed at the 4 o'clock position**, making it nearly invisible from the front. In **1964**, this was a bold visual statement to the world that the watch was a ""pure automatic,"" allowing the elegant, uninterrupted symmetry of the case to take center stage.

Masterful ""Weekdater"" Dial Symmetry: The dial of the **427990** is a study in functional luxury, featuring a radiant sunburst silver finish and **hand-applied, multi-faceted baton indices**. The arched day-of-the-week window at 6 o'clock and the date window at 3 o'clock provided an organized, professional aesthetic. The applied **""5"" shield logo** and the Suwa factory symbol remain hallmarks of this era’s high-status branding, prioritizing sophisticated clarity for the global businessman.

A Landmark of Suwa ""Active Dress"" Heritage: Produced in **1964**, the 427990 remains one of the most culturally significant ""early 5s"" for collectors. It often features the iconic **Dolphin etching** on the case back, symbolizing its reliable water resistance and ""Sports"" pedigree. It stands as a testament to an era when Seiko combined **mechanical innovation with a timeless aesthetic**, creating a reliable companion for the men who built modern, post-war Japan.

For more information, please look at the pictures.

Notes

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