Offered in this auction by Second Vintage This significant Seiko Lord Matic represents a fascinating transitional period in Japanese watchmaking history, featuring the desirable "Waterproof" caseback designation that was phased out shortly after its production. As a high-grade automatic timepiece positioned just below the Grand Seiko and King Seiko lines, this Reference 5606-7140 combines a robust monocoque case design with an elegant silver sunburst aesthetic. It stands as a testament to the Suwa Seikosha factory's ability to produce exceptionally finished watches that offered accessible luxury to the 1970s market. Brand: Seiko Model: Lord Matic Reference Number: 5606-7140 Serial Number: 090351 Movement: Automatic Caliber 5606 Dial: Silver Sunburst Case Size: 36 mm (excluding the crown) Case Material: Stainless Steel Production Year: 1970 Condition: Good vintage condition Dial and Hands The watch features a classic silver sunburst dial that remains in an attractive state of preservation. It is adorned with applied steel baton indices featuring crisp black inlays that match the slender handset, ensuring excellent legibility. The applied "Seiko" and "LM" logos add depth to the face, while the framed day and date window at the 3 o'clock position provides practical utility. The dial surface is clean and reflects the light beautifully, characteristic of Seiko's high finishing standards from this era. Case and Crystal The stainless steel case utilizes a clever one-piece, or monocoque, construction labeled "Open Thru Glass," designed to improve water resistance and structural integrity. The case form is a distinct cushion shape with flowing lines that hug the wrist comfortably. Being a vintage piece, the case shows honest signs of use, including visible surface scratches and contact marks on the bezel and case sides consistent with its age. The caseback inscriptions are deep and fully legible, proudly displaying the "Waterproof" marking which allows for precise dating to September 1970. Movement Powering the watch is the highly regarded Seiko Caliber 5606, a 23-jewel automatic movement known for its reliability and thin profile. This sophisticated mechanism offers both hand-winding and hacking capabilities. The movement is performing exceptionally well, with timegrapher results showing +5 to +7 seconds per day with strong amplitude, which indicates a very healthy movement offering reliable vintage performance. Strap The watch is fitted with a classic black leather strap featuring a crocodile-style embossed pattern. The strap is in excellent condition and complements the dressy yet versatile nature of the silver dial, making it ready for immediate wear. Condition This Lord Matic is assessed as being in Good vintage condition. While the case displays expected evidence of wear such as light dings and scratches on the polished surfaces, the edges remain well-defined. The dial is the highlight, presenting a clean and crisp appearance that balances the vintage character of the exterior. It is an honest, unpolished cohesive example that looks fantastic on the wrist. Dimensions The case measures 36 mm in diameter excluding the crown, a classic proportion that offers significant presence without being overbearing. The monocoque design allows for a relatively slim profile, ensuring it slides easily under a shirt cuff. Remarks This 1970 Seiko Lord Matic is a wonderful example of the brand's golden era of mechanical watchmaking. The presence of the "Waterproof" stamp on the caseback makes it a collectible variation, as Seiko transitioned to "Water Resistant" very shortly after this watch was manufactured. It combines historical significance with daily usability. History Introduced in 1968, the Lord Matic (LM) line was created to bridge the gap between Seiko's mass-market offerings and the high-end Grand Seiko and King Seiko models. The LM series was equipped with the completely new 5600 series movement, which was thinner and more advanced than its predecessors. These watches became immense hits in Japan due to their high-quality finishing, reliable movements, and diverse case designs, securing their place as icons of Japanese horology. 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: SEI-SLJ-0056