Introduction This is a Seiko Precision 15-jewel open-face pocket watch, hand-wound, with a crisp white dial carrying bold Arabic numerals, blued-steel hands, and a subsidiary seconds sub-dial at the 6 o'clock position inscribed 'Second Setting Diaflex'. The exterior caseback is stamped 国鉄四国 No. 150, identifying this as inventory piece number 150 issued to the Japanese National Railways Shikoku Region (国鉄四国). The movement is signed SEIKOSHA and bears 15 jewels, and the watch is presented on its original-style snake chain with a uniform clip. Historical / Era context Seiko's open-face railway pocket watches, produced under the Seikosha name and later branded Seiko Precision, formed the backbone of Japan's punctual train operations for decades, with the Type 19 lineage serving JNR from 1929 through the 1970s. The caseback engraving 国鉄四国 (Japanese National Railways, Shikoku Region) with an individual inventory number confirms this was an officially issued and numbered service watch, not a civilian piece. The SEIKOSHA movement signature places this within the classic lineage of Seiko's in-house railway-grade calibers. Condition The watch is running and keeping good time. The watch was checked lying flat (dial up) after a full wind. This is a spot check at the time of listing; as a vintage mechanical watch the rate in actual wear varies with position and winding state, and long-term accuracy is not guaranteed. As a vintage timepiece it may benefit from a service. Case: The case body and caseback show scattered fine scratches and surface scuffs consistent with regular service use. The exterior caseback carries noticeable scratch coverage across its centre field. The bezel rim shows light edge wear. Overall the case retains its original form without dents or deep gouges. Dial: The white dial is legible with all numerals and the subsidiary seconds track clearly readable. There is mild age-related toning and light soiling visible across the dial surface, particularly around the lower half. No significant cracks or chips are present. Crystal: The crystal is intact with no cracks. Light surface scratches are present on the crystal face, consistent with normal service wear. Movement: The watch is running. With the caseback opened, the SEIKOSHA-signed movement is visible, finished with straight-grained bridges and a three-quarter plate layout. The movement is rated at 15 jewels, including visible ruby jewels in polished brass settings. The regulator lever is present and the balance runs freely. Accessories: The watch is accompanied by a snake-link chain with a uniform bar clip. No original box or papers are included. Please review all photographs carefully for the detailed condition. Specifications Brand: Seiko Model: SEIKO PRECISION 15 JEWELS Movement: Manual winding mechanical movement Jewels: 15 jewels Case material: Stainless steel Case diameter: approx. 50.2 mm Total length including crown: approx. 63.1 mm Total length including crown and ring: approx. 71.4 mm Dial color: White Period: 1950-1959 Weight: approx. 109 g Accessories: Snake-link chain with bar clip In working order: Yes Timekeeping: keeping good time (checked lying flat after a full wind) Closing note A rare, individually numbered Japanese National Railways Shikoku Region service pocket watch — a genuine piece of JNR operational history that is increasingly hard to find with its provenance intact. Please examine all photographs carefully, as they form part of the description. As with all vintage timepieces, please examine the provided photographs carefully to satisfy yourself with the condition before bidding. The watch is sold as a vintage collectible; water resistance and future maintenance are not guaranteed. The item is carefully packed and shipped from Japan with tracking. Import duties, taxes and customs charges are the buyer's responsibility.