Seiko Grand Seiko 'Serviced' 5646-7020 (1973)

Now available at auction from Second Vintage Colored dials on vintage Grand Seikos are highly sought after by collectors, and this vibrant green dial 56GS is a striking example. Featuring a beautifully textured vertical gradient surface beneath a distinctive faceted crystal, this timepiece pairs exceptional visual character with a highly capable high-beat movement. Brand: Seiko Model: Grand Seiko Hi-Beat Reference Number: 5646-7020 Serial Number: 313349 Movement: Automatic Dial: Green gradient with vertical brushing texture Case Size: 36 mm (excluding the crown) Case Material: Stainless Steel Production Year: 1973 Condition: Good vintage condition. Movement serviced on 6 August 2026. Timegrapher: +12+14s/day, performing remarkably well. Dial and Hands The dial features a stunning, vibrant green gradient finish with a distinct vertical brushing texture. The applied indices and logos are clean and well preserved, with no visible staining, moisture damage, or print loss. The hands retain a clean polished finish, showing no visible oxidation, corrosion, or scratches, matching the exceptional preservation of the dial. Case and Crystal The stainless steel case retains sharp lines and strong original geometry, presenting honest wear with moderate surface scratches and handling marks throughout. The original gold GS medallion is intact and in good condition on the caseback. Some pitting is visible on the case perimeter under the caseback. The watch features a signed crown with crisp knurling and the GS logo. A faceted mineral crystal protects the dial, displaying clearly visible edges and generally clear surfaces with minor wear. Movement Powering this watch is the automatic Caliber 5646A, featuring engravings noting 25 jewels and adjustments to five positions and temperature. The movement appears generally clean, with the rotor and bridges showing normal light wear. Dirt and pitting are visible on the case sealing area outside the movement. Recording +12+14s/day on the timegrapher, it is exhibiting remarkable accuracy and consistency, performing brilliantly for a vintage timepiece. The movement was serviced on 6 August 2026. Strap The watch is fitted with a period correct stainless steel link bracelet. The bracelet displays moderate surface scratches and normal wear, and accommodates a maximum wrist size of 17.5 cm. Condition Good vintage condition. The movement was serviced on 6 August 2026 and, supported by the recorded timegrapher result, is performing very strongly. The dial and hands are stunningly preserved, free of moisture damage or oxidation. The case maintains sharp geometry but shows moderate scratches and handling marks, along with some pitting on the case perimeter under the caseback and on the sealing area outside the movement. The gold GS caseback medallion remains well preserved. The faceted crystal and period correct bracelet exhibit regular surface wear. Dimensions 36 mm (excluding the crown) Remarks This 56GS stands out for its highly sought-after green gradient dial and distinctive faceted crystal. The combination of its vibrant visual presence and a well-adjusted high-beat movement makes it a compelling addition for any enthusiast of classic Japanese watchmaking. History The Grand Seiko 56GS series was produced by the Suwa Seikosha factory in the early 1970s, representing one of the final mechanical Grand Seiko families before the quartz era fully transformed the industry. Powered by the high-beat caliber 5646 running at 28,800 vibrations per hour, the series is celebrated for its slim profile and refined engineering. Colored dials from this period are particularly sought after, offering a striking departure from the more traditional silver and white variants typically found in the Grand Seiko catalog. / Second Vintage SKU: SEI-GHB-0001