Serviced Vintage 1967 JAPAN SEIKO BUSINESS-A 8306(46)-8020 27J Automatic.

Vintage 1967 JAPAN SEIKO BUSINESS-A WEEKDATER 8306(46)-8020 27Jewels Automatic.

Welcome to my auction!

Item description

Movement :

• Pet name : BUSINESS-A .
• Caliber No. : 8346A.
• Movement : Automatic.
• Beat rate : 18000bph.
• Year of manufacture start : 1966's.
• Factory : Suwa.

Externals :

• Serial No. : 7400263.
• Dial No. : JAPAN 8306-8030T AD.
• Glass : Acrylic.
• Case size : About 35.25mm.
• Lug width : 18mm.
• Band : New Leather Strap of SEIKO original.

Condition :

• Used, it runs well.
• ONE PIECE CASE
  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 10:00 and 1:00
• The day difference time of an used watch is about +-1 minute / day.
• Overhaul service in September 2026.
  The movement has been cleaned and oiled, so it works fine.

Key Features

• The Sovereign Peak of Mid-60s Business Class Luxury (1967): Manufactured in 1967—a landmark year during Japan's high-growth economic miracle—the Seiko Business-A (Business Automatic) represented Suwa Seikosha's dedicated line engineered specifically for rising corporate executives. Sourced under reference 8306-8020 (also cataloged with movement designation 46), this high-grade mid-1960s model offered a sophisticated bridge between the Seikomatic-R series and the upper-tier Lord Matic lineup.
• The Over-Engineered 27-Jewel Caliber 8306 Automatic Heart: Powering this historic timepiece is the revered 27-jewel Caliber 8306A, an in-house automatic engine operating at a steady frequency of 18,000 vibrations per hour (vph). Equipping an executive watch in 1967 with an ultra-high 27-jewel specification minimized friction across critical gear-train pivots. This movement features modern executive conveniences including hacking seconds, quick-set date operation, and smooth manual-winding capability.
• Architectural "8020" Case Geometry and Low-Profile Lines: The reference 8306-8020 is globally distinguished among vintage collectors for its classic, broad-shouldered stainless steel case architecture. Designed with sharp, faceted lugs and sweeping, zero-distortion mirror-polished bevels adhering to early "Grammar of Design" principles, the low-profile case allows the watch to slide effortlessly under a tailored shirt cuff.
• Masterful "Weekdater" Dial Harmony and Executive Clarity: The dial of the 8306-8020 showcases outstanding visual balance, featuring a radiant silver sunburst canvas decorated with hand-applied, multifaceted rectangular hour indices. Symmetrically framed at 3 o'clock, the dual-calendar window houses a full day-of-the-week display alongside the date wheel, proudly signed with the stylized applied "Business-A" logo and "27 JEWELS" typography above 6 o'clock.
• An Investment-Grade Masterpiece of Suwa's Executive Legacy: Manufactured in the milestone mechanical year of 1967, the 8306-8020 27-jewel Business-A remains a highly coveted, universally respected cornerstone reference for vintage Seiko collectors. It captures the exact historical era where Seiko created specialized executive lines for Japan's emerging corporate leaders, built to an uncompromising, heirloom-grade standard.

For more information, please look at the pictures.

Notes

• Before buying.
  The vintage watches we sell are inspected and adjusted so they work fine. However, since it is an vintage watch, Please purchase on the assumption that it will be repaired.
  
  
• To prevent shipping accidents.
  Please monitor the tracking number until the item arrives and if it stagnates, please investigate at your country post office. Also, please confirm the item when you receive the item.
  
  
• About import taxes.
  Taxes such as import duties and VAT are not included in the item price or shipping charges, except for items shipped to the US. When you purchase, you will likely be required to pay these fees in your country.
  
  
• About Payment, Shipping, Return.
  Payment, Shipping, Return are in accordance with eBay's business policies.