Hi Guys,
While the facts in the Goodall book are not incredibly well documented and clearly somewhat suspect since they come from Seiko themselves, they are still useful as one reference at least.
According to Goodall, in 1967, Seiko took 2nd (Daini Seikosha) and 3rd (Suwa Deikosha) places at the Neuchatel international chronomoter competition (pictures of some official looking documents are printed in the book) and in early 1968 submitted a movement to the Neuchatel Observatory that bested the results of the previous year's winner.
According to Goodall, Seiko "then" entered the Geneva Observatory competitions (presumably later chronologically based on the wording, but no dates are given) and took every place from 4th through 10th, securing a first place overall for the company.
Goodall didn't make the claim (that I saw, it's been awhile since I read the book) that Seiko's successes were in any way related to the termination of the Observatory Competitions and it is somewhat telling that Seiko switched their research heavily away from mechanical chronometers to quartz at around the same time. I think this was indicative of the general direction of the industry (everyone could see the writing on the wall regarding the accuracy attainable with quartz) at the time and likely a leading factor in the termination of the competitions.
Did getting beat by the Japanese on their own playing field have something to do with it? It seems to me like it very well may have, but how large a factor it may or may not have been is really impossible to say. It does make for a GREAT story though and surely an interesting focus for further research. If I read either French or Japanese I'd be a lot more likely to actually attempt such research myself however. 
_john