Seiko Lord Marvel A 1968 model, 5740-1990, featuring a hand-wound 5740a movement and an elegant sandblasted blue dial. Model History: The Seiko Lord Marvel was Japan's first mass-produced high-frequency wristwatch, first released in the late 1960s. Powered by the 5740A caliber, this watch was a turning point in Seiko's pursuit of mechanical precision and formed the basis for later Grand Seiko developments. Specifications: Reference: 5740-1990 Serial number: 4500420 Year of manufacture: April 1968 Movement: Seiko caliber 5740-1990 Serial number: 4400420 Year of manufacture: 1968 Movement: Seiko caliber 5740A Year of manufacture: April 1968 Case material: Stainless steel Case diameter: approx. 36mm (excluding crown), 38mm (including crown) Ear spacing: approx. 42mm Ear width: 19mm Dial: Blue "sand" textured Crystal: good Strap: New brown leather