VTG 1958 Seiko Cronos Calendar 21J 14K Gold Filled Watch J14061A RUNNING Patina

Up for sale is a rare, historically significant piece of Japanese horological history: a first-year production 1958 Seiko Cronos Calendar (Self-Dater).

Introduced in 1958, the Cronos line represented a major leap forward for Seiko's mid-century luxury offerings. This specific model features the sought-after "Calendar" script at the top of the dial, a highly advanced feature for its era.

Condition & Summary:

Case: Gorgeous 14K Gold Filled case (Reference 314061A). The case has been carefully and lightly cleaned to remove surface tarnish while preserving its original lines and vintage character. Shows honest wear and thinning on the lug edges consistent with its 65+ year history.

Dial: Features a highly distinct, heavy "tropical" moisture patina. The text "Calendar" at the top and "21 Jewels Diashock" at the bottom remain faintly visible. Perfect for collectors who love the "wabi-sabi" aesthetic or for a historic restoration project.

Movement: Seikosha 21-Jewel manual wind movement with Diashock protection.

Exceptional Mechanical Performance (Timegrapher Tested):

Despite the cosmetic dial patina, the internal movement is running beautifully. It has been tested on a multifunction timegrapher with impressive metrics for a watch from 1958:

Rate: +7 seconds/day (Excellent, near-chronometer daily accuracy)

Amplitude: 241° (Strong power delivery from the mainspring)

Beat Error: 0.8ms (Well within healthy operational tolerances)

Specifications:

Brand: Seiko

Model: Cronos Calendar / Self-Dater

Year: January 1958

Case Material: 14K Gold Filled Front / Stainless Steel Back

Jewel Count: 21 Jewels

Features: Date window, Diashock anti-shock system

Selling strictly AS-IS as a fully functional vintage piece with heavy cosmetic dial patina. Please review all photos carefully, including the timegrapher reading. Shipping securely packaged via USPS.