Grail Found: Ultra Rare Seiko For Sale

There’s a pleasure in pouring a glass of malt, putting one’s feet up and trawling through the watch listings on eBay. Although bargains aren’t as common as they once were, there are still plenty of interesting things to be found. And one always learns about something new.

Having just finished writing about Grand Seiko for worn&wound yesterday evening, I thought I’d nip over and see what was on the block from the Japanese favorite. I was just pouring a second glass (a Macallan, since you asked) when I spotted something as the page rolled past. I scrolled on for a second, simply because I couldn’t believe what I’d just seen.

No, it can’t have been. There aren’t any left outside museums and serious private collections, surely?

By the time I had the description and pictures open in front of me, I realized I’d spotted a piece of watchmaking history–a 1968 Seiko Astronomical Observatory Chronometer!Grand Seiko Observatory Chronometer-1



This was like wandering through the local car auction and finding the Mk IV Ford GT40 that won Le Mans in 1967 hidden behind a couple of scrap Mondeos.

The watch is owned by a well-known Japanese watch collector in Tokyo. My Macallan forgotten, I sent him a note asking about it. He replied almost immediately, despite the eight hour time difference. He also kindly passed on his research into its history, which I’ve incorporated into this article.

The term “rare” gets sprinkled around the watch world like fairy dust. Almost every auction catalog is packed with rarities. But the cal. 4520 Astronomical Observatory Chronometer truly is rare. Seiko only made 73 in 1968. Unfortunately, they chose 18ct gold for the cases. And if that wasn’t special enough, Seiko proceeded to make the dial and hands out of gold, too. And that sealed its fate.Grand Seiko Observatory Chronometer-4

Bling Becomes Unfashionable

In 1968, this was splendid. It was the year of the Shelby Mustang GT500–a car so hairy-chested it should have come with a medallion and a pair of flared Levis in the glove box. But times changed. Not only did bling become unfashionable, but where in ‘68 gold was $43.50 an ounce, by 1980 it was $595. And as watches now went bleep and lit up when you pressed a button, who wanted those boring old wind-up things? Anything from the unfashionable 1960s in a gold case had only one destination–the smelting pot.


No one knows how many Observatory watches were stripped, their movements dumped, the dials ripped off and the cases scrapped for their gold value. But, unfashionable and thought too valuable to leave intact, that’s just what happened.

Why All the Fuss About Accuracy?

Grand Seiko Observatory Chronometer-3Today, with even a £10 Casio being accurate enough to beat the -4/+6 second COSC standard, accuracy’s not a big deal. Watch buyers expect it. In 1963, when a Seiko quartz clock, the Crystal Chronometer, finished in the top 10 of the Neuchâtel Observatory chronometer accuracy contests, accuracy was a lot harder to come by. It was also a field dominated by the Swiss. So Seiko coming 10/10 in the accuracy trial mattered. It was the first time a non-Swiss maker had reached the top 10. The Japanese watchmaker might as well have walked down the Quai Philippe-Godet waving a banner saying “We’re coming for you.”


Buoyed by their success, in 1964, the two Seiko plants–Suwa Seikosha and Daini Seikosha–submitted wristwatches for assessment. The results? A disappointing 144th for Suwa Seikosha and 153rd for Daini Seikosha. It looked like the Japanese weren’t quite coming for the Swiss just yet.

Obsessional Watchmaking

But the level of determination at Seiko’s two manufactures was now set to obsessional. When Daini Seikosha discovered one of the reasons for their poor showing in ‘64 was down to a magnetized hairspring, they fixed the problem. Then, just to make sure, they sent their next watches for the competition on a special route to Switzerland to minimize the effect of the earth’s magnetic fields. In case that wasn’t enough, the watchmakers lined the shipping cases with anti-magnetic alloy.  Grand Seiko Observatory Chronometer-8It wasn’t just magnetism that Seiko wanted to eliminate. They started filling their watch cases with hydrogen to avoid any chance of rust on the components.

Seiko Neuchatel
’67 Neuchâtel Observatory’s Bulletin de Marché; source:

Fast-beat movements–even as high as 72,000 bph–and bimetallic balances were next. Clearly, a little thing like knowing nothing about bimetallic balances wasn’t going to bother Seiko’s engineers, so they set-to with a blank sheet of paper and a will. And with that, they developed a bimetallic balance movement from scratch that they entered in the 1967 competition. Omega took the first place spot, but the Daini Seikosha entry was breathing down their neck in second and the third place spot was snagged by a delighted Suwa Seikosha team.



Far be it from anyone to accuse the Swiss of being sore losers, but the next year they changed the rules. Even so, the Suwa Seikosha 1968 entry was considerably more accurate than Omega’s winning entry the previous year. The Neuchâtel authorities promptly canned the competition.

In the same year, despite there being no competition at Neuchâtel, Daini Seikosha sent the Observatory 103 movements for certification–and 73 of the 36,000 bph cal. 4520 movements passed as chronometers. And it was these movements that found their way into 18ct gold cases to be sold as Astronomical Observatory Chronometers. Each came with its own certificate of accuracy–the Neuchâtel Observatory’s Bulletin de Marché.

Designed for Accuracy Rather Than Looks

“This movement was handmade made by those obsessional watchmakers at Daini Seikosha. This movement was timed at Neuchâtel and certified as one of the most accurate in the world. It represents the pinnacle of mechanical watches’ accuracy achievements before quartz moved in and took over the market.”

You might expect a watch of this standard to boast a seriously decorated movement. Not a bit of it. The plates carry anglage, but apart from some graining, that’s your lot. This is an engine designed for high-performance, not haute horlogerie peering at. Think Bugatti. And the technical magic is certainly there–even the hacking lever is in three articulated parts.Grand Seiko Observatory Chronometer-6

Now to the Big Question

What will the watch sell for? The only Astronomical Observatory Chronometer with Cal. 4520 movements that reached the market in the last few years made $40,000. Mr. Hokugo believes the dial on his watch may have been reprinted and there are no papers, boxes or an original strap with it. But this is, make no mistake, a piece of history. This movement was handmade made by those obsessional watchmakers at Daini Seikosha. This movement was timed at Neuchâtel and certified as one of the most accurate in the world. It represents the pinnacle of mechanical watches’ accuracy achievements before quartz moved in and took over the market. There were only ever 73 of them, and no one knows how few are left.



As I write this, there are four days until the auction closes and the price is a daftly low $1,325.88.

Now, if you’ll excuse me I have to finish this Macallan. Then, I have an appointment with a gentleman at a crossroads to see how much I can get for a rather well-used used immortal soul.

With grateful thanks to the owner in Tokyo.

Images from this post:


Related Posts
Mark developed a passion for watches at a young age. At 9, he was gifted an Omega Time Computer manual from a local watch maker and he finagled Rolex brochures from a local dealer. Today, residing in the Oxfordshire village of Bampton, Mark brings his technical expertise and robust watch knowledge to worn&wound.
markchristie mark_mcarthur_christie