Presented for auction by Second Vintage This Grand Seiko 5646-7010 represents a magnificent era of Japanese watchmaking, capturing the essence of the "Grammar of Design" established by Taro Tanaka. The 56GS series is widely celebrated for housing one of Seiko's most refined and reliable automatic movements of the period, offering a harmonious blend of precision engineering and understated elegance. The presence of the gold medallion on the caseback further cements its status as a premium offering from the Daini Seikosha or Suwa Seikosha lineage, making it a highly desirable piece for collectors who appreciate the historical significance of vintage Grand Seiko. Brand: Seiko Model: Grand Seiko Reference Number: 5646-7010 Serial Number: 122633 Movement: Automatic, Caliber 5646A, 25 Jewels Dial: Silver sunburst, applied indices, showing light, even aging and minor spotting Case Size: 36 mm (excluding the crown) Case Material: Cap Gold Production Date: February 1971 Condition: Good vintage condition, honest wear with a well-preserved dial and medallion Dial and Hands The dial features a classic silver sunburst finish that catches the light beautifully, accented by applied faceted baton indices with black central stripes for enhanced legibility. The applied "SEIKO" and "GS" logos are crisp and prominent. A framed day-date window at three o'clock displays the day in both English and Kanji. The dial shows signs of age, including some light spotting and minor discoloration around the extreme outer edge near the chapter ring, consistent with vintage aging. The dauphine hands are well-proportioned, exhibiting some surface oxidation and aging that align with the character of the dial. Case and Crystal The 36mm Cap Gold case showcases the sharp, faceted lines characteristic of Tanaka's design philosophy. The transition between the brushed upper surfaces and polished flanks remains visible, though softened by age and wear. The case exhibits overall surface scratches, minor dings, and some wear to the gold capping, particularly around the lug edges and bezel, which is typical for a watch of this vintage. The flat crystal is clear, allowing an unobstructed view of the dial. The caseback features a well-preserved gold "GS" medallion, a hallmark of vintage Grand Seiko authenticity, surrounded by clear engravings indicating the reference and serial numbers. Movement Powering this timepiece is the automatic Caliber 5646A, a 25-jewel movement renowned for its Hi-Beat 28,800 bph frequency. The movement is visibly clean, with the rotor and bridges showing appropriate finishing. The engravings "ADJ. 5 POS. TEMP." highlight the chronometer-grade adjustments typical of Grand Seiko. Exhibiting remarkable accuracy and consistency, performing brilliantly for a vintage timepiece. The timegrapher displays a reading of -8 to -12 s/d. Strap The watch is fitted with a black leather strap featuring a crocodile-grain pattern and contrasting tan stitching. It is secured with a standard tang buckle, providing a comfortable and classic pairing that complements the gold tones of the case. Condition This Grand Seiko is in good vintage condition. The case shows honest, expected wear with softening of edges and some loss to the Cap Gold finish, while the dial has developed a mild, even patina with localized spotting. The gold medallion on the caseback is remarkably intact, a significant plus for collectors. Dimensions Case Size: 36 mm (excluding the crown) Remarks This 5646-7010 is a testament to Seiko's dedication to precision and design during the 1970s. The combination of the Hi-Beat movement, Kanji day wheel, and the iconic case shape makes it a quintessential vintage Grand Seiko, offering both historical value and timeless style. History The Grand Seiko line was introduced in 1960 with the goal of creating the "ideal" watch, focusing on precision, durability, and beauty. The 56GS series, launched in the early 1970s, was one of the last mechanical Grand Seiko lines before the quartz crisis fully took hold. It was designed to be slimmer and more automated in its production while maintaining the strict Grand Seiko standard of accuracy, marking a significant milestone in Seiko's horological journey. Payment and Shipping Payment must be completed within 1–3 days after purchase. Your watch will be professionally and very securely packaged, and shipped with tracking and insurance for your peace of mind. We ship via fast express service, with typical delivery in 1–4 business days (destination dependent). Note that with vintage watches, minor signs of wear, aging, or imperfections may be present and are considered normal for watches of this age. Please review all photos carefully before bidding. We strive to photograph each watch from multiple angles for the most accurate representation. The photos form an important part of the description. If there are any concerns of functionality or defects after delivery, make sure to contact us within 3 days of receiving the watch so we can assist you. As with all vintage watches, water resistance is not guaranteed. If you have any questions, feel free to contact us after the auction ends. / Second Vintage SKU: SEI-SGH-0001