This Seiko "Blumo" (Blue Sumo) SBDC003 is a quality Seiko watch from it's first generation. It has the slant written "Automatic" on it and misses the newer "X" …
Yet another Seiko SBDC003 / SBDC 033 review – Small Toys for Grown Men
Sold : Seiko 1st gen blue SUMO(Blumo) sbdc003 $280 | The Watch Site
Seiko Sumo: Forever Cursed To Live Between Two Budgets (Haiku Review)
FS: Seiko Sumo Blumo SBDC033 | WatchCharts
FS: Seiko King Sumo (Blumo) | WatchUSeek Watch Forums