question, more in an informational rather than rhetorical fashion, is K. Seiya:
At this page: www32.ocn.ne.jp .html#chrono )
In the middle of 1960's, European Chronometer Official Association appealed that Seiko shouldn't use the name Chronometer. Because of that, Seiko was unable to use the name of Chronometer. With this appeal, Seiko, Daini Seikosha and Suwa established stricter group internal standard for quality which was called GS standard. Seiko watches which had this Chronometer declaration began to be use the name of Grand Seiko according to company internal GS standard. (62GS,44GS) At the same time, the Japan chronometer approval organization was organized, and officially approval started in 1969. (however, because of rise of quartz it was closed in 1983) Chronometer of 45,56,52 King Seiko did PASS this official approval.
About astronomical observatory Chronometer Concours
From 1964, Daini Seikosha Co.,Ltd and Suwa Seikosha Co has participated in a department of Neuchatel at astronomical observatory Concours .
In the first participation, Daini got 153th place grade and Suwa got 144th grade. Order is suddenly raised afterwards. Only three years later, Daini got 4,5,7,8th and Suwa acquired 12th in 1967. With regard to the series prize, Omega won the best, Daini got the second and Suwa got the third prize. But the Concours was stopped suddenly by the year. The contents of Concours was an examination of astronomical observatory Chronometer standard precision for 45 days. Watches passed that examination became certificate "astronomical observatory authorization Chronometers". Each watch manufacturer submitted special movement produced only for the Concours .
Most of them were not good for commercial market as they were too high precision, not durable.
But this 45GS was marketed after it passed this astronomical observatory Chronometer (only 73 units of 100 were PASSed))
There were only two companies who could sell watches passed astronomical observatory authorization Chronometer in those days. ---Seiko and Giraud Peregaux. "