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The Encyclopedia of Horology

Wristwatch · Manual-wind wristwatch

Omega Ranchero Seamaster Ref. 2990-1

Partially verified

This Omega Ranchero Seamaster wristwatch, reference 2990-1, is a manual-wind timepiece dating to 1959. It features a 36mm stainless steel case and is powered by the Omega Caliber 276 manual movement. The dial is characterized by a double-signed configuration, incorporating both the 'Ranchero' and 'Seamaster' markings. The aesthetic includes luminous radium-filled hands and applied hour markers, which exhibit patina. The dial further displays the '30mm' text, indicating the movement family, which the source notes was recognized for accuracy and durability. The watch is currently fitted with a third-party leather strap supplied by the vendor. The movement is identified by the serial number 163xxxxx.

Front view of the Omega Ranchero Seamaster showing the black dial with sub-seconds and dual signature.
Front view of the Omega Ranchero Seamaster showing the black dial with sub-seconds and dual signature. — Bulang and Sons. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
www.bulangandsons.com
Category
Wristwatch · Manual-wind wristwatch
Maker / attribution
Omega
Reference
2990-1
Catalogue / lot identifier
Source URL identifies the listing
Source-reported date
1959
Source-reported place
Not established
Source-reported serial
163xxxxx

Source-reported attribution and specifications are not independent authentication. A listing does not establish present ownership, current display, availability or permission to reproduce.

Object description

Case and Dial Design

The watch is housed in a 36mm stainless steel case featuring the configuration specific to the Ranchero model. It displays a clear '30mm' designation, referring to the movement caliber family used within the piece.

The layout incorporates a sub-seconds register positioned at the 6 o'clock mark. Luminous radium material is applied to the hour markers and the hands, which show evidence of age-related patina. The dial layout includes prominent triangular indices at the cardinal positions and shorter markers throughout the perimeter.

Evidence for this section
  • “36mm steel case”
  • “Rare double-signed Ranchero Seamaster dial”
  • “The “30mm” on the dial refers to the movement family of the time”
  • “patina in the radium-filled hands and hour markers.”

Movement and Functionality

The timepiece is powered by the Omega Caliber 276, a manual-wind movement. This movement originates from the 30mm caliber family, which was marketed for high levels of accuracy and structural durability during its period of use. The movement is recorded with the serial number 163xxxxx.

The watch functions as a time-only instrument with a dedicated seconds sub-dial. The vendor reports that the movement has been inspected and regulated by their watchmaker to ensure operational condition.

Evidence for this section
  • “Cal 276 manual wind movement”
  • “The “30mm” on the dial refers to the movement family of the time, which was regarded as one of the most accurate and durable.”
  • “Movement serial 163xxxxx”
  • “The watch has been fully checked and regulated by our watchmaker”

Model History and Authenticity

The Omega Ranchero was introduced in 1958 and produced for approximately two years. Due to this limited production window, the model is classified by the source as a rare tool watch. This specific example features the additional Seamaster signature, which is not found on all Ranchero-labeled pieces.

The watch is presented on a leather strap provided by the vendor.

Evidence for this section
  • “Introduced in 1958, it was only available for two years making it a very rare watch indeed.”
  • “This example is EXTRA special since the dial also features the SEAMASTER signature”
  • “Omega Ranchero ref 2990”

Open research questions

  • What is the specific production timeframe for the Seamaster-signed dials compared to standard Ranchero dials?
  • Can the movement serial 163xxxxx be used to narrow the production date beyond the general 1959 attribution?

Source evidence

Recorded claims and source quotations for Omega Ranchero Seamaster Ref. 2990-1
FieldSource-reported valueSource quotation
Reference2990-1“ref.2990-1”
Date1959“Dates to 1959”
Case Size36mm“36mm steel case”
MovementOmega Caliber 276“Cal 276 manual wind movement”
Serial Number163xxxxx“Movement serial 163xxxxx”
Dial InscriptionRanchero Seamaster“Rare double-signed Ranchero Seamaster dial”

Visible details

  • Triangular luminescent hour markers
  • Sub-seconds dial at 6 o'clock
  • Broad arrow-style hour hand
  • 36mm steel case with straight lugs

Research qualifications

  • Patina on radium markers and hands is consistent with age but not independently verified
  • The exact production volume is not specified beyond being identified as a rare short-run model

Photograph identity and source facts were screened before import; rights clearance remains pending.

Consulted source

ساعت مچی وینتیج Omega مدل Ranchero Seamaster رفرنس 2990-1

Reviewed 2026-11-02 · Record 621dec9cc4

Terms in this record

Glossary explanations for terms named in this object’s record.

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