The Grand Seiko 56GS series is closely related to the King Seiko 56 series as well as the Seiko Lord Matic. All of these watches house the Seiko 5600 series of movements produced by Suwa Seikosha. The 56GS was released in 1970, just two years after its King Seiko counterpart. The 56GS features a higher finishing quality as well as an upgraded 5640 series movement that was regulated to higher standards compared to the King Seiko.  

This watch features a custom engraved case back that, when translated, reads "1973 - 25 Years of Service Award Commemoration - Tokyo Shibaura Electric Co., Ltd." Tokyo Shibaura Electric was the previous name for the Toshiba Electronics Company. This engraving appears "stock" from the Grand Seiko factory. These watches were likely a custom run from Grand Seiko for Toshiba to gift to their employees. 

- Ref No. : 5641-7000
- Serial No./Year: 345275-/-1973
- Case:
    37mm diameter, 18mm lug width, 10.6mm thickness, 42mm Lug-to-lug.
    Stainless Steel
- Crystal: Acrylic
- Movement & Accuracy: 
    Caliber: Suwa Seikosha Cal. 5641 AUTO
    Complications: Central Hacking Seconds
    Measured Accuracy: -2 sec/day.
    Amplitude: 180°
    Beat Rate: 28,800 A/h
- Band: Replacement Leather Strap
- Condition Rank: (A) Very Good Condition. Please See Photos and Condition Rank Guide.
- Country of Manufacture: Japan

Condition Rank Guide:
-NOS: Item is in New Old Stock condition (NOS). Shows little to no signs of wear apart from some minor handling wear.
-A+: Item is in Excellent condition. Micro-scratches can be seen on the sides of the case, bezel, and/or bracelet. No pitting/gouges on the case or scratches in the crystal.
-A: Item is in Very Good condition. Minor scratches and scuffs can be seen on the sides of the case, bezel, and/or bracelet. No pitting/gouges on the case or deep scratches on the crystal.
-B: Item is in Good condition. Moderate scratches and scuffs can be seen on the sides of the case, bezel, and/or bracelet. Minor pitting/gouges may be visible on the case. One or less deep scratches may be visible on the crystal. See photos.
-C: Item is in Fair condition. Heavy scratches and scuffs can be seen on sides of the case, bezel, and bracelet. Significant pitting or gouges are visible on the sides of the case and the crystal shows multiple deep scratches
-NR: Item is in Non-Running condition. Item is not functional. For parts or repair only.