Step back into the golden era of Seiko with this beautiful Sealion M55 Weekdater from May 1965. This reference is a quintessential piece of 1960s Japanese horology, blending executive style with the robust "Sealion" case engineering that made Seiko a household name. The Details • Brand: Seiko • Model: Sealion M55 Weekdater • Reference: 6206-9000 • Serial Number: 5500414 (Dating it precisely to May 1965) • Movement: Caliber 6206B – Automatic, 26 Jewels (A high-spec movement for the era) • Case Material: Electro Gold Plated (EGP) / Stainless Steel Back • Case Size: approx. 37mm (excluding crown) • Dial: Sunburst Silver with applied gold markers and a unique "crosshair" design • Complications: Day-Date (English day wheel with red Sunday/blue Saturday accents) • Strap: New aftermarket brown leather strap with alligator grain Condition Report This watch is a true survivor, showing an honest patina that collectors love. • Dial & Hands: The sunburst dial remains crisp with its original applied logos and hour markers. The gold hands are in excellent condition. • Case: The gold plating shows some characteristic wear on the lugs and bezel edges, revealing the history of the piece. The stainless steel caseback features the iconic Sealion logo, which remains visible despite some surface scratches. • Movement: The 26-jewel automatic movement is remarkably clean (as seen in the photos) and is running. Note: As with all vintage timepieces, a service is recommended for daily precision. • Crystal: Shows some light surface marks consistent with age but maintains great clarity. Why Bid on This Watch? The Sealion M55 was positioned as a premium, water-resistant executive watch in the mid-60s. The 6206 movement was a precursor to the legendary 62MAS and 62GS lines, making this a significant "missing link" for any serious Seiko collector. With its hidden crown at 4 o'clock and the framed day-date windows, it offers a sophisticated, symmetrical aesthetic that still looks contemporary 60 years later. Don't miss the chance to own a genuine piece of Seiko's mid-century history. Shipping: Fast, insured, and well-packaged worldwide.