Vintage 1966 JAPAN SEIKO SEIKOMATIC-R 8305-8010 30Jewels Automatic.

Vintage 1966 JAPAN SEIKO SEIKOMATIC-R 8305-8010 30Jewels Automatic.

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

Item description

Movement :

• Pet name : 83 SEIKOMATIC-R.
• Caliber number : 8305C.
• Movement : Automatic.
• Beat rate : 18000bph.
• Year of manufacture start : 1965's.
• Factory : Suwa.

Externals :

• Serial number : 6400156.
• Dial number : JAPAN 8305-8000S AD.
• Glass : Acrylic.
• Case size : About 35.1mm.
• Lug width : 18mm.
• Band : New Leather Strap.

Condition :

• Used, it runs well.
• Quick set(Day/Date) : Okay.
  Set of the date : The set at one stage pulling the crown.
• 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.
• Some film peeling is visible on the dial.

Key Features

The Sovereign Peak of Mid-60s Refined Executive Luxury (1966): Manufactured in **1966**—a milestone historical year during Japan's high-growth economic boom and horological golden era—the **Seiko Seikomatic-R** reference **8305-8010** represented Suwa Seikosha's elevated dress watch platform. Bearing the prestigious **""R""** (""Refined"") moniker, this high-grade reference served as the flagship date-only executive timepiece bridging the Seikomatic line with top-tier King Seiko models.

The Over-Engineered 30-Jewel Caliber 8305 Automatic Engine: Powering this historic instrument is the revered **30-jewel Caliber 8305A**, an in-house automatic engine operating at a steady frequency of **18,000 vibrations per hour (vph)**. Equipping a dress watch in **1966** with an extraordinary **30-jewel specification** minimized friction across critical gear-train pivots, delivering exceptional long-term rate stability while featuring **hacking seconds** and quick-set date operation.

Architectural ""8010"" Classic Dress Case and Recessed Crown Integration: Sourced in a solid stainless steel case, the reference **8305-8010** is globally recognized for its sharp, broad-shouldered case architecture. Adhering to early **""Grammar of Design""** principles with sweeping lug chamfers and broad zero-distortion mirror-polished bevels, the low-profile case integrates a signature **recessed crown at 4 o'clock** for an uninterrupted, symmetrical wrist silhouette.

Immaculate Date-Only Dial Harmony and High-Jewel Typography: The dial of the **8305-8010** is a study in mid-century visual restraint and high-contrast clarity. Free from day-window clutter, it features a radiant silver sunburst canvas set with **hand-applied, multifaceted rectangular hour indices** and sharp dauphine hands, neatly balanced by the framed date aperture at 3 o'clock and the stylized **""Seikomatic-R 30 Jewels""** designation above 6 o'clock.

The Sovereign Gold Dolphin Case Back Medallion Heritage: The ultimate hallmark of this 1966 treasure rests on the case back: the iconic **solid gold-embossed or deeply engraved Seiko Dolphin medallion**. Certifying its elite factory-regulated precision and water-resistant construction, the 8305-8010 30-jewel Seikomatic-R stands as an eternal, investment-grade cornerstone reference for serious vintage watch collectors worldwide.

For more information, please look at the pictures.

Notes

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