Available now on auction by Second Vintage This is a remarkable opportunity to acquire a significant piece of Japanese horological history, a Grand Seiko 56GS from the golden era of the brand. As one of the most practical and collectible vintage Grand Seiko references, this Hi-Beat model combines the legendary "Grammar of Design" case aesthetics with a robust automatic movement. The presence of the intact gold medallion on the caseback and the highly desirable "Waterproof" stamping dates this specific piece to the very transition period of Seiko case markings, adding a layer of rarity for collectors. Brand: Seiko Model: Grand Seiko Reference Number: 5646-7000 Serial Number: 048013 Movement: Automatic Hi-Beat Caliber 5646 Dial: Silver Sunburst Case Size: 36 mm (excluding the crown) Case Material: Stainless Steel Production Year: 1970 Condition: Excellent vintage condition with a very clean dial and a well-preserved case structure, running with impressive accuracy for its age. Dial and Hands The watch features a classic silver sunburst dial that remains in exceptional condition, reflecting light beautifully. It is adorned with sharp, multi-faceted applied baton hour markers and a framed day-date window at the 3 o'clock position. The applied "Seiko" and "GS" logos are crisp and raised, adding depth to the face. The dauphine-style hands are faceted and polished, legible and sharp, retaining their original elegance without signs of corrosion. The text is sharp and black, featuring the Suwa factory logo above the 6 o'clock marker. Case and Crystal The stainless steel case features the distinct C-shape or cushion design associated with the 7000 reference, offering a bold presence on the wrist while maintaining classic proportions. The case lines remain defined, showing honest wear consistent with careful vintage usage. The signed "GS" crown is present and correct. A standout feature of this example is the caseback, which proudly displays the 18k gold GS medallion in excellent, intact condition, a detail often lost or damaged on similar models. The "Waterproof" engraving on the caseback further confirms its early production run. The crystal is clear and presents well, allowing for an unobstructed view of the dial. Movement Powering this timepiece is the renowned Caliber 5646 automatic movement. This is a "Hi-Beat" movement operating at 28,800 vibrations per hour, a technical marvel of its time designed for high precision. The movement is winding smoothly and offering reliable vintage performance. Timegrapher testing indicates the watch is running between -3 and -6 seconds per day with strong amplitude, which indicates a very healthy movement that is ready for daily wear. Strap The watch is fitted with a high-quality black leather strap featuring contrasting white stitching. The strap is in excellent condition and complements the sport-dress aesthetic of the steel case, making it ready to wear immediately. Condition This example is in excellent vintage condition. The dial is virtually flawless, which is the most critical aspect for value. The case shows minor surface scratches typical of a watch from 1970 but retains its architectural integrity. The gold medallion on the caseback is a highlight, preserved beautifully. Mechanically, the watch is performing admirably within strict vintage tolerances. Dimensions The case measures 36 mm in diameter excluding the crown, a classic size that wears slightly larger due to the cushion case shape. It fits comfortably under a shirt cuff while commanding attention as a piece of fine watchmaking. Remarks The 56GS series represents one of the most successful and reliable lines in Grand Seiko history. finding a "Waterproof" stamped 5646-7000 with such a clean dial and an intact gold medallion is becoming increasingly difficult. This watch offers the perfect blend of daily wearability and serious collector credibility. History Grand Seiko was established to create the "ideal" watch, capable of competing with and surpassing the highest Swiss standards of precision and beauty. By the late 1960s and early 1970s, they had achieved this goal. The 56GS line, introduced around 1970, was the last great mechanical series before the quartz revolution fully took hold. This specific watch, produced in April 1970, stands as a testament to the peak of Seiko's mechanical watchmaking prowess during the 20th century. Payment and Shipping Payment must be completed within 1-3 days after purchase. The watch will be securely packaged and shipped with tracking and insurance for your peace of mind. Please review the pictures carefully before bidding. We strive to showcase the watch from multiple angles for an accurate representation. As with all vintage watches, water resistance is not guaranteed. The watch will be delivered in fully functional working condition. If you have any questions, feel free to contact us after the auction ends. / Second Vintage SKU: SEIYZQCF50000