Authentication & condition
How we verify a vintage watch before you buy it
Short answer
Every candidate goes through an eight-point inspection in hand: identity and dating from serial and case reference, dial originality under magnification, hand and lume consistency, case polishing assessment, bezel and crystal correctness, movement inspection with the case open, timing measurement, and completeness of bracelet, box and papers. The result is a written report in English that states what is not original before it states anything else. We do not issue certificates of authenticity — we give you the evidence and let you decide.
- Inspection
- In person, case opened, 10x–20x magnification.
- Photographs
- Typically 20–40 per candidate, including macro dial and movement shots.
- Timing
- Rate and amplitude recorded on a timing machine where the movement runs.
- Disclosure rule
- Non-original parts are listed first, in plain English.
- Included in
- Every brief. There is no separate authentication fee.
- Not offered
- Certificates of authenticity, insurance valuations, investment advice.
Some dealers will not allow photographs. The inspection happens on the dealer's premises, so photography is at their discretion, and a few will not permit the case to be photographed open. Where that happens we tell you exactly what we could photograph and what we could not. If a dealer allows no photographs at all, we will say so and generally advise against the watch — you would be approving a purchase on our word alone.
The eight-point inspection
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Identity and dating
Case reference, movement calibre and serial number are recorded and cross-checked. On Seiko, the case-back serial gives production month and year — the first digit is the last digit of the year, the second is the month, with O, N and D standing for October, November and December. If the serial says 1971 and the movement stamp says 1968, something has been swapped, and the report says so.
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Dial originality
Under 10x to 20x magnification we look at print edge quality, font generation, marker alignment, the seat of applied logos, and whether lume plots sit in aged original cups or fresh recesses. Three outcomes are possible: original, factory service dial from a later period, or refinished (redial). All three are stated explicitly; only the first commands full value.
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Hands and lume
Hand shape is compared against period catalogues, and hand lume is checked against dial lume for colour and texture. Matching, evenly aged lume is one of the strongest signals that a watch has been left alone.
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Case and polishing
Lug thickness is measured, chamfers and Zaratsu facets are photographed against a straight edge, and case-back engraving depth is assessed. Heavy polishing rounds edges, thins lugs and blurs hallmarks — irreversible, and frequently the difference between two prices that look inexplicable side by side.
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Bezel, crystal and crown
Insert font and colour, crystal profile and part number, crown signature and thread condition. These are the parts most often replaced during service, and the ones sellers most often assume are original.
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Movement, case open
Calibre confirmed against the reference, replacement parts identified, service marks read, rust and water damage assessed, and the winding, setting and complication functions tested. If a seller will not allow the case to be opened, we do not recommend the watch.
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Timing
Rate in seconds per day, amplitude and beat error are measured on a timing machine in multiple positions where the movement runs. A watch that needs service is not a problem; a watch whose owner did not know it needed service tells you something about how it has been kept.
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Completeness
Bracelet reference and end-link correctness, clasp stamping, number of links, inner and outer box, guarantee booklet, hang tags and any service invoices. We note what is missing as clearly as what is present.
How Japanese condition grades translate
Japanese dealers use a shorthand grading vocabulary that machine translation renders uselessly. Here is how we read it — and note that grades describe appearance, never mechanical health or originality.
| Japanese | Reading | What it usually means |
|---|---|---|
| 新品 | shinpin | New, unused, with original packaging. On a vintage watch, treat as new old stock and verify. |
| 未使用品 | mishiyō-hin | Unused but stored — gaskets and lubricants are still decades old. |
| 極美品 | goku-bihin | Excellent. Near-flawless appearance; often means recently polished, which is not a virtue. |
| 美品 | bihin | Very good. Light wear, no significant damage. |
| 良品 / 中古美品 | ryōhin | Good used condition. Visible wear consistent with age. |
| 訳あり | wake-ari | "There is a reason" — a known fault, disclosed but frequently not specified. Always ask what. |
| ジャンク | janku | Junk / for parts. Sold as non-functioning, no returns. Sometimes exactly what a restorer wants. |
| オーバーホール済 | ōbāhōru-zumi | Serviced — but by whom, when, and with which parts? Ask for the invoice. |
| 社外品 | shagai-hin | Aftermarket part. Common for crystals, crowns and bracelets. |
| 文字盤リダン | mojiban ridan | Redialled. Honest sellers state it; many do not. |
The full list, including auction and trade terms, is in the glossary.
Common questions
- How can you tell if a vintage Seiko dial is a redial?
Under 10x to 20x magnification, original printing has crisp, slightly raised edges and the correct font generation for the period. A redial typically shows soft or blobby text, misaligned minute markers, wrong spacing around the applied logo, paint bridging the date window edge, and lume plots sitting in fresh recesses instead of aged original cups. A factory service dial is a genuine part from a later production run — identifiable by a newer font or missing text such as the water-resistance line — and sits between original and redial in value.
- How do you date a vintage Seiko watch?
From the case-back serial: the first digit is the last digit of the production year, the second is the month, with O, N and D for October, November and December. That yields a month and a decade, and the calibre plus case reference resolve the decade. We then cross-check against the movement stamp — a mismatch normally means a swapped movement or case.
- Does polishing really matter that much?
Yes. Polishing removes metal permanently. On models defined by flat, mirror-finished facets — Grand Seiko, King Seiko, many 1960s dress cases — a polished example can be worth a half or a third of a sharp one. This is the single most common reason two seemingly identical listings differ wildly in price.
- Will you sell me a franken watch?
Only knowingly. If a watch has a replacement dial, a later bezel or a swapped movement, the report says so and the price reflects it. What we will never do is present a mixed-part watch as original.
- Do you provide a certificate of authenticity?
No, and we would treat anyone who does for vintage Japanese watches with caution. There is no issuing authority. What you get instead is documented evidence — photographs, serials, measurements — that you or any watchmaker can independently check.
- Should I have the watch serviced before shipping?
Usually yes if you intend to wear it, and no if you collect for originality — a service replaces gaskets and sometimes parts. We quote overhauls per movement through an independent watchmaker in Japan and always ask before replacing anything.
Page last reviewed 19 August 2026.
Every brief includes this inspection
There is no separate authentication fee. If we cannot inspect a watch properly, we do not put it in front of you.