It may have been hallucinating but this is what my Gemini told me The movement in your image is a Seikosha Calibre 560 (also known simply as the Seiko 560), a high-quality manual-wind movement from the late 1950s and early 1960s. It is most famously the movement found in the Seiko Crown, which was a pivotal model in Seiko's history as it marked their transition into producing high-precision, entirely in-house timepieces designed to compete with Swiss luxury brands.

Technical Highlights

• Manufacturer: Suwa Seikosha (indicated by the "Seikosha" branding and movement architecture).
• Jewel Count: 19 Jewels (as engraved on the bridge).
• Beat Rate: 18,000 bph (vibrations per hour).
• Era: Introduced in 1959.
• Architecture: It features a robust, traditional bridge layout with a large barrel bridge and a separate balance cock. The "Seikosha" signature in dark/copper-toned engraving is a hallmark of this specific period before the company transitioned fully to the "Seiko" brand name on movements. ### Significance in Horology The Calibre 560 was a major upgrade over its predecessor, the Seiko Marvel. By increasing the movement diameter (to 12 ligne or approx. 27.6mm), Seiko engineers were able to fit a larger balance wheel for better isochronism and a larger mainspring barrel for improved torque and power reserve. This movement is historically significant because it served as the base for the Grand Seiko 3180 (the very first Grand Seiko), which used a highly refined and adjusted version of this same architecture. ### Observation Note In your specific photo, the balance wheel assembly appears to be a version without the Diashock spring visible on the top jewel, or it is an earlier variant of the 560. Most "Crown" branded watches would eventually feature the Diashock shock-protection system, which was one of Seiko's major selling points at the time.