Confirming Originality
The 4th Series World Time from SEIKO
Model No. 6117-6400 and 6117-6409
Buying vintage is complicated.
It requires a keen eye for detail, patience, and often times more information and interaction between the buyer and the seller.
However, the pay off is clear.
The value of a vintage watch increases substantially when all of the key components can be confirmed as original.
It is also satisfying to own and wear a watch that is a time capsule from another era.
This article provides some detail on confirming the originality of your 4th series SEIKO world time watch.
It is based on the author's personal experience collecting these watches, as well as insights shared from other collectors and owners, cross-checked against the Image Data Study.
The Movement
This watch received an updated movement from the previous series, the 6117B. It is nearly identical to 6117A, which it replaced, the only difference being the addition of a hacking seconds feature. It should be easy to confirm that the seconds hack (stop) when the crown is pulled out to change the time. The 6117B model number is also easy to spot when the case back is opened.

There are at least two different variations of the 6117B found in these models, documented here. One marked DAINI SEIKOSHA, the other just SEIKO,

Dial and hands, removed from case during service. Note the V-shaped knotch at 4:30 (between the 8 and 9 markers on the 24 hour ring)

Dial-side of movement during service. Note the black dot betwteen the 12 and 13

Disassembled pieces ready for cleaning

Assembled movement with caseback removed

SEIKO SEVENTEEN 17 JEWELS 6117B JAPAN

6117B DAINISEIKOSHA CO.,LTD. JAPAN SEVENTEEN 17 JEWELS UNADJUSTED

Assembled movement with caseback removed

Marking on inside of case back

This movement has upgraded (non-original) 3rd and 4th wheel bridge bushings upgraded to jewels. Note the beveled edges on the plates on these earlier movements.

This movement has the standard (original) 3rd and 4th wheel bridge bushings. Note the straight edges on the plates of these later movements.
NOTE: The barrel bearings are a common wear point on this movement (the 6117B). Some watch makers offer a barrel jewel upgrade for both the mainplate and barrel bridge. This process takes the movement from 17 to 19 jewels.
The Dial
The dial can be tricky to confirm, especially for the untrained eye.
In addition to seeing dials from previous series used as transplants, there are also many after-market dials.
Some look very similar to the originals.
Others are clearly meant to look different - perhaps a nod to the SEIKO modding culture.
Here are the seven most common original dials:







Other Original Dial Variants
It appears that there was a run of dials and hands without lume, in late 1974 through early 1975. There are no known catalog or ad scans, but the data attributes seem to align, and these additional dials are likely original, and uncommon.


NOTE: There are several other dial colors that appear infrequently. Some are believed to be after-market creations. Here's a quick run down:
- Black dial with yellow 24-hour ring - these are likely sun-bleached red/orange dials
- Silver or White dial with orange 24 hour ring - after-market
- Silver or White dial with black and blue 24 hour ring - after-market or swapped with a previous series
Details to Confirm on the Dial
And here is a quick check list of the items to confirm.
- The correct color(s), finish and overall look
- Correct dial code for the dial color
- The placement of WORLD TIME vs the Production Date on the case back
- Date stamp on the back of the dial (when servicing)
- A few common after-market tells
Correct Dial Code
This one is easy to check.
- Original white (and golden hue) dials with lume will have dial code JAPAN 6117 | -6420T.
- Original white dials without lume will have dial code JAPAN 6117 | -6424T.
- Original black dials with lume should have dial code JAPAN 6117 | -6400T.
- Original black dials without lume should have dial code JAPAN 6117 | -6404T.
- After-market white dials are out there with the -6400T code on them.






Here is a shortcut to view after-market white dials with incorrect dial codes:
Placement of WORLD TIME
This one is still under review.
Based on available data, it appears that the vast majority (over 92%) of watches with WORLD TIME printed at 6-o'clock were manufactured in 1969 or 1970.
As of this writing, it is not clear if the position of WORLD TIME should follow strict manufacture date windows, but it is much more likely that a dial with WORLD TIME at 6-o'clock is in the correct case if the production date is in 1969 or 1970.
Date Stamp on the Back of the Dial
This one requires a complete disassembly of the watch.
If a seller says that the watch was serviced recently, it is worth asking if any photos of the back of the dial were taken at that time.
Otherwise, if/when you send your watch in for service, be sure to check this small detail.
Original dials should have a 2-digit code stamped (in ink) on the back side.
As a general rule, the date stamp on the dial should match the first two digits of the serial number on the case back, or possibly proceed it by a month or two.
So, if for instance your serial number starts with "13", then a matching dial would likely be stamped as "13", "12" or "11".
If they don't match within a couple of months it is not necessarily proof of a swapped dial or case.
However, when they do match its more evidence that the dial is likely original to the case.



A Few Common After-market Tells
Three common after-market "tells" are the SEIKO logo itself, golden indices on a non-gold watch, and the text on the 24-hour ring.






Also of note, only gold watches should have golden or yellow tinted dial, bezel, applied indices and hands.
Here is a shortcut to view all cataloged watches flagged as having an incorrect dial:
The Hands
First the GMT hand.
It is unique to this watch in the World Time series, and the same on both dial colors.
NOTE: this same GMT hand is also used on the "Navigator GMT" 6117-6410.
Second, the hour and minute hand.
Aside from confirming the obvious shape, size and lume, also note that the white and black dial have different hands.
Original white dial watches include hour and minute hands with a black stripe down the center.
This is not just a light reflection in photos.
Original black dial watches do not have this detail.



The Bezel
There are 7 original bezels to consider.
First, a golden / yellow tinted bezel, with GMT and London stack at the same timezone position.
This belongs only on the gold version of the watch, manufactured in 1972.
After that, there are 3 black bezels and 3 silver bezels.
Original white dial watches had the silver bezel.
Original black dial watches had the black bezel.
Both the Black and the Silver bezels come in three versions.
The first two are the so-called "Error Bezels" - which accurately separated London from GMT time, through 1971.
The third, again correctly, stacks GMT and London from 1972 and onward.
It is common to see a mismatch of bezel vs case production date.
Bezels with London and GMT listed side by side, and Moscow Dharan should be in cases produced through December 1970.
Bezels with London and GMT listed side by side, and Moscow-Riyadh should be in cases produced in 1971 through early 1972.
Bezels with London and GMT stacked should be in cases produced in early 1972 and onward.







Also note the texture of the bezel under magnification.
There is a distinct concentric ring pattern.
Follow the link below for a more detailed look at the evolution of the cities bezel:
The Date Wheel
The date wheel on the 6117-640X is the same one used on the 6117-601X.
The wheel is white with all black numbers.
Earlier 6217 models included a different date wheel font.
Follow the link below for a more detailed look at the evolution of the date wheel:


The Case
The case is different from previous series, and easy to distinguish.
It is however shared with an adjacent model, the "Navigator GMT" 6117-6410.
It may seem obvious, but it is worth double checking the case back to make sure it has the correct model number designation.
The screw-down case back itself can also be swapped out, as it is shared with a broader set of SEIKO watches.
Examples of other 6117 and 6119 case backs have been identified.
Finally, a note on the case finish.
About 14% of cataloged examples have a brushed finish, typically with a circular brush pattern around the center axis of the case.
As of this writing, many of the cataloged examples with brushed finish include other non original details.
Also, all but one example (that is obviously not original) are 6117-6400 models.
It is unclear if this was an original finish option.
All NOS (New Old Stock) examples to date has a high polish finish.




Original Bracelets
The "Railroad" Bracelet
The OEM bracelet for this watch is commonly referred to as the "Railroad" bracelet. Here are some detail photos of the bracelet, clasp and end links.









The Stelux H-Link Bracelet
Some 6117-6400's sold in the Asian Pacific were sold on a Stelux H-Link bracelet. There are many SEIKO bracelets that look similar to this one and work in ongoing identifying the correct version.



Related Articles

The Seiko World Time 6117-640X
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Old Ad Scans: Seiko World Time 6117-640X
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The Seiko World Time 6117-6409 in Gold
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Reference Cities - Changes over the Years
A history of changes to the Cities Bezel on SEIKO World Time mechanical watches from 1964 through 1976

The Date Wheel - Changes over the Years
A history of changes to the Date Wheels on SEIKO World Time mechanical watches from 1964 through 1976

The Dial - Changes over the Years
A history of changes to the Dials on SEIKO World Time mechanical watches from 1964 through 1976

Authenticating The Seiko World Time 6217-7000
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