Seiko - Emblem Deep Midnight Blue Tonneau Cushion - 4120-5000

This exceptionally rare mid-1970s luxury dress instrument is an authentic JDM artifact from June 1975, as definitively verified by the serial number 565371 stamped across the solid stainless steel caseback alongside the revered Daini Seikosha lightning bolt emblem. Produced under Seiko’s prestigious, design-forward Emblem line, this reference was curated specifically for discerning Japanese executives seeking avant-garde case geometry and understated haute-horlogerie simplicity. It houses the high-grade Daini Seikosha Caliber 4120 quartz movement, an over-engineered electronic caliber built without the distraction of a ticking seconds hand or calendar window, emphasizing pure, uninterrupted two-hand luxury timekeeping. 

The case architecture presents a fluid tonneau cushion chassis crafted from solid stainless steel, distinguished by meticulous vertical brushing across the broad hooded lug surfaces and contrasting polished bevels. The dial is a breathtaking centerpiece, featuring a rich, velvety deep midnight blue surface that transitions subtly to obsidian under direct light. It is appointed with slender applied silver baton hour indices, an applied silver Emblem stylized crest at 6 o'clock, polished needle hands, and a discreet perimeter dot track. Completed on its original, period-correct factory stainless steel multi-row beads-of-rice style bracelet with signed XBA-170 end-links, this 1975 Daini creation delivers fluid, seamless wrist ergonomics.