Within the world of vintage Seiko, Grand Seiko – distinguished by the “GS” on dial/crown and gold medallion on its caseback, like on this full serviced 1968 Grand Seiko 4520-8000 here – with its distinctive "Grammar of Design," inhabits the top of the food chain - simple as that.
 
Grand Seiko – with 51 different models – were simply the most painstakingly designed and exquisite watches made by Seiko, produced by both the Dani and Suwa factories, including the 45GS hi-beat line here.  Grand Seiko’s 45GS series holds the position of the second, and final, series to be manufactured by the Daini Seikosha division of Seiko, with 19 of the 51 models produced in the end. 
 
Seiko used three calibres in the 45GS series – the 4520A (no date), 4522A (with date), and the always impressive 4580 VFA (Very Fine Adjustment).  Seiko produced four case variations for its 4520A and 4522A mechanical movements, with each rather closely adhering to its famed “Grammar of Design” philosophy.
 
Speaking of the Grammar of Design, in the early 1960s, Seiko hired a young designer by the name of Taro Tanaka, who created a set of design principles he called “The Grammar of Design.”  In 1962, Tanaka noticed Swiss watches "sparkled brilliantly" and realized the design of high-end Seiko watches could be radically improved through the implementation of "flat and conical surfaces perfectly smooth and free of distortion."
 
This "Grammar of Design" was implemented in Grand Seiko and King Seiko lines from 1967 and made these lines instantly recognizable as status symbols in the hierarchical Japanese business world of the 1960s and 1970s.
 
Tanaka’s rules would go on to fundamentally change Seiko’s design language.  All surfaces and angles of the case, dial, indices and hands had to be flat and geometrically perfect to best reflect light.  Following this aesthetic, the bezels were to be simple two-dimensional faceted curves.  And third, no visual distortion from any angle was allowed, and all cases and dials had to be mirror-finished.  In “A Journey in Time: The Remarkable Story of Seiko,” Tanaka’s approach to the new style is described as follows:

“He started by creating cases and dials that had a perfectly flat surface, with two-dimensional curves on the bezel as a secondary feature. Three-dimensional curves were not used, as a general rule. He also decided that all distortion should be eliminated from the dial, too, so that it could be finished with a mirror surface. This formed the basis for the new Seiko style.”
 
Make no mistake, the GS marked, and still marks, the very best Seiko has to offer, easily on par with the vast majority of what Switzerland has to offer by way of competition.  And the 4520 represents one of the highest achievements of Grand Seiko – namely, creating one of the best watches on the planet.  Period.
 
This Grand Seiko comes on a leather strap, with nylon strap, rugged travel case, and springbar tool.