State of the collection – the 45GS movements

A write up of the vintage Grand Seiko watches in my collection that utilise the 45GS movements.

Since there are over 40 pieces in the collection, it makes sense to break this “state of the collection” write-up over several articles. Each post will cover a specific movement – or set of movements – from the vintage Grand Seiko releases, and include photos of the watches I have that utilise that movement.

Whilst I don’t intend these articles to provide a comprehensive and thoroughly researched scholarly history of vintage Grand Seikos, I will share some knowledge on the pieces that I have picked up over the course of the last year. If I get anything wrong, please don’t hesitate to let me know!

Grand Seiko 4520-7000
Grand Seiko 4520-7000

The 45GS series started production in 1968, continuing through until the early 1970’s. Like the earlier and short-lived 44GS series, they were produced by the Daini factory.

Whilst utilising only three different movements – the dateless 4520A; the 4522A with a date complication; and the incredibly rare 4580 Very Fine Adjusted, there were a good variety of case and dial designs created over this period.

Ignoring for now the VFA models – I shall return to those at the end, there are four different case designs used for both the 4520- and 4522- models. For once, from what I can ascertain, there is complete symmetry between the date, and dateless models, with the same case and dial combinations available for both.

First up is the aggressively angled -7000 case. As seen in the lead photo of this post, this was available in a cap gold variant, as well as a stainless steel version seen below in a 4522-7000.

Grand Seiko 4522-7000
Grand Seiko 4522-7000

Whereas the cap gold cased versions were only available with a white linen-textured dial, the stainless steel examples can be found with white, blue, and black dials.

Next up are the -7010 cased watches. Despite these being extremely common and very easy to pick up for relatively low prices, I seem to have somehow missed adding an example of either variant to my collection – a gap that I will get around to filling in due course!

The -7010 cases are oval in shape, with a brushed stainless steel finish. Whilst the vast majority of watches that you will come across have white dials, there are some black dialed versions out there as well. I need to do some more research on these black dials because I’m not entirely convinced they are original – if someone can verify for sure that they are, please let me know so that I can set the record straight here.

Grand Seiko 4520-8000
Grand Seiko 4520-8000

Next, pictured above in its original box, is the more traditionally designed 4520-8000, and below, the equivalent 4522-8000 with the date complication –

Grand Seiko 4522-8000
Grand Seiko 4522-8000

Both of these models were also available with cap gold cases, retaining the same model number, and I have an example of the 4520-8000 in cap gold in my collection –

Grand Seiko 4520-8000 Cap Gold
Grand Seiko 4520-8000 Cap Gold

The final case design used in the regular 45GS models is my favourite of the lot, and carries the -8010 designation.

Available only in 18K solid gold, it is – I hope you would agree – an absolutely beautiful case, with a wonderfully linen-textured finish to the upper side of the case.

My example is the 4520-8010, and is one of my favourite pieces in the entire vintage Grand Seiko range.

Grand Seiko 4520-8010
Grand Seiko 4520-8010

I’m pretty sure that this is the exact same case that was also used for the legendary Seiko Astronomical Observatory Chronometer.

Finally, rounding out this write-up of the 45GS watches in my collection is a model utilising the 4580 “Very Fine Adjusted” movement.

4580’s can be considered the “grail of grails” as far as vintage Grand Seiko movements are concerned. Whilst it is probable that the stainless steel and platinum variants of the original 3180 – and possibly also the solid 18K gold 5722’s – are rarer watches, my collection is of course built around the movements, so from my perspective, the 4580 is the absolute pinnacle of the collection.

Grand Seiko 4580-7010 VFA
Grand Seiko 4580-7010 VFA

The example in my collection is the 4580-7010 that you can see above. My particular watch dates from July 1970.

As you can probably anticipate given how few of these watches were created, it is extremely rare to come across one for sale. In fact, the example pictured above is the only -7010 I have seen for sale in the last 18 months.

Dial detail from the Grand Seiko 4580-7010 VFA
Dial detail from the Grand Seiko 4580-7010 VFA

Similarly rare is the 4580-7000 model, again of which I have only seen a single example come to the market. The -7000 has a uniquely designed case that is unlike any other vintage Grand Seiko case.

If you are after either of these watches and ever see one for sale, my advice is to simply pay the asking price immediately, because you never know when another might come up!

Whilst I am unsure as to the numbers of steel and platinum 3180’s that were made, nor sure of how many 5722’s in 18K Gold there are, it has to be said that I have seen multiple examples of each of these rare pieces come to the market in the last 15 months or so, but just a single example of each 4580 VFA.

Happy hunting!

Post script –

There are many conflicting write-ups on the internet regarding the 4520 Astronomical Observatory Chronometer and the 4580 Very Fine Adjustment movements.

Depending on what you read and where, the story is either –

ALL Neuchatel certified 4520 movements (73 pieces) and 4580 movements (153 pieces) were used in the Seiko (not Grand Seiko!) Astronomical Observatory Chronometer that has the model number 4520-8020. Thus, there are supposedly 73 AOC’s out there with 4520 movements, and 153 with 4580 movements – making for a total of 226 Astronomical Observatory Chronometers. Then, additional 4580 movements were created (how many is not stated) which were used in the 45GS VFA’s.

The alternative interpretation is that only the 4520 movements were used in the AOC, and the 4580 movements are those that you find in the 4580 VFA’s. In other words, there are just 73 AOC’s, and 153 VFA’s.

If anyone reading this can clarify what the true situation is (with proof!), I’d be very appreciative – please don’t hesitate to leave a comment below.


1 thought on “State of the collection – the 45GS movements”

  1. Nice examples of the 45 family there!

    Regarding the movement used in the AOC models:
    I doubt I can offer any proof of what was actually in there, but have 2 “observations”
    1. In the pictures I’ve seen of the AOC examples, I’ve never seen a movement showing an actual calibre# stamped/engraved on it. Thus, it could be that Hattori Corp., while using a 45 calibre “base” really did not consider any of the AOC movements to strictly be either a 4520 or a 4580, but some “unnumbered” calibre (there is some historical basis for conjecturing this as Hattori did not assign official calibre #s to such things as the 1st Generation King Seiko that preceeded the cal. 44A, and the original Lord Marvel movement that preceeded the 5740A). Even the calibre “60M” Goldfeather was un-numbered officially, the “60M” simply refers to a Parts Catalog number shown in a table sub-titled “to be used only when the movement has no Cal. No.”

    2. From information I received from Tachy-san, the 3rd digit of the calibre# in the 61 & 45 families of Grand Seiko simply designated adherence to a particular Seiko Accuracy Grade {Mens}. In the case of “2” [as in 4520], it informed that the movement was adjusted to the “AA” [“normal” Grand Seiko for Men] grade while the “8” indicated it adhered to the “VFA GS for Men” standard or “AAAA”. In the case of an Astronomical Observatory movement, there was a separate standard that had very different characteristics than any other Grand Seiko grade and apparently was NOT provided for in the calibre numbering “scheme” for the 61 & 45 movement families. Thus, by the definition of that scheme, a 45×0 movement that was adjusted to “AOC” standard really did not have an “official” 3rd digit value. Thus, it may be incorrect (technically) to call any of the AOC movements either 4520 or 4580.

    To expand on the issue of the 3rd digit of calibre#, please refer to a copy of the GS grade chart I posted @ [top item in that database entry]

    Looking at Daily Rate, the “AA” grade (as for a 4520) shows -3 to +5, while for “AAAA” [4580] has -2 to +2 BUT the AOC has -8 to +8.

    In terms of other criteria in the chart, the AOC does not match data shown for the 4520 [“AA” grade] (while 4580 is not given or does not exist).

    Thus, it would seem that IF (as Tachy-san determined) the 3rd digit is supposed to represent the accuracy level of the GS movement in question, then neither “2” nor “8” are really appropriate values to use in any potential numbering of an AOC movement, which then gives more credence to my 1st point – that I’ve never actually seen a calibre# officially stamped on an AOC movement.

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