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Bezel insert

6139-600x internal tachymeter ring

Probable

The rotating tachymeter ring inside the crystal on the 6139-600x, turned by the crown at 4. Replacement rings are produced in quantity; numeral spacing and the tone of the ring against the dial are the checks.

Part reference

Brand
Seiko

Documented variations

Classification

FactoryDocumented as shipped from the factory for this reference and period.PeriodNot original to this watch, but correct for its production period.ServiceFitted by the manufacturer's own service network. Not a defect.AftermarketThird-party part. Affects originality, not authenticity.ModifiedGenuine parts in a configuration the factory did not sell. Affects originality and value, not authenticity.CounterfeitDeceptive reproduction intended to pass as genuine.UnknownEvidence on file does not settle the question.

  • Replacement ring

    AftermarketProbable

    Whole production

    A common and frequently disclosed restoration part on a fifty-year-old chronograph. Note it; do not weight it.

Documented on these references

Provenance of this record

Sources & Evidence

Secondary sourceSpecialist publication

Fratello Watches — Seiko 6139 and the Pogue

Fratello Watches

Accessed
2026-08-18

Cited for

This referenceProbable
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Last verified: Not yet reviewed