Collectible! Circa 1940s Seiko Seikosha Cal 10B 1740 Mini-Seconds, 15 Jewels Mechanical Watch (OH)

Make: Seiko
Type: Mechanical
Model: Seikosha Sub-Seconds Dial
Year of Production: Circa 1940s - 1950s
Movement / Case: Caliber 10B / 1740
BPH: 18,000
Number of Jewels: 15
Hand and Dial: 3D Gold-Filled Arabic / Baton Indices with Dauphine Hands
Width: 30mm
Lug to Lug Height: 38mm
Thickness: 9mm
Lug Width: 15mm
Bracelet / Strap: Hi-Quality Vintage Expendable SS Bracelet
Pouch / Box: Brand-New EVA Type Zipper Pouch

Prior to the production of their own movement, Seiko used to purchase watch movements from Europe, namely the English brand, Moeris.

Here we have a Seikosha mechanical movement built circa 1940s to 1950s with a sub-second hand dial that is separate from the main movement. This watch was produced prior to the formation of the DAINI and SUWA separate factories.

This gorgeous Seikosha, Model 10B is a 15 Jewel Mechanical timepiece that is breathtaking in  so many ways that brought Seiko into the limelight as a serious watchmaking company that can now contend with the Swiss, English, German and American "big boys."

For Seiko Collectors and Vintage fans, this is a Seikosha Cal 10B in a 1740 case in excellent condition as one can see.

This seldom seen vintage Seikosha has a pearl white main dial with 3D lines running parallel across the dial, and a silver sub-second dial located at the 6H position. The dial and 14K solid-gold Arabic+ Baton indices and Leaf hands underwent a good and thorough cleaning to reveal pure class in well preserved form albeit a slow build-up of patina throughout the dial. The crystal was replaced.

The classical designed case was also cleaned via ultrasonic immersion to remove age marks, and miniscule hairline scratches caused by aging were buffed away.

The crown is located at the traditional 3H positions and nicely tucked away to prevent damage or snags. The crown is original and was reduced in size compared to the 1930s Seiko mechanical movements.

The movement was carefully stripped and meticulously cleaned via ultrasonic immersion, oiled, re-assembled and calibrated on 11 March 2024. Hence, it underwent an overhaul and should be able to operate unhindered until the next servicing thereby providing the owner peace of mind.

Equipped with a Seikosha 10B movement constructed from stainless steel, it has 15 Jewels and operate at 18,000 BPH. The time-grapher, after 60 hours of calibration, shows excellent readings i.e. rate of +6 seconds every 24 hours and amplitude of 103! Such readings are exceptional even by brand new modern automatic watch standards whereby the accepted tolerance is -20 to +40 seconds a day! This is a testament to the quality, excellent power reserve, the meticulous care provided over the years, and the painstaking expert calibration.

To the best of our knowledge and expertise when overhauling the timepiece, the watch is 100% original Seiko components from this particular watch. No parts were replaced with aftermarket or modified parts.

The case width and height are approx. 30mm (w/o crown) and 38mm respectively. The lug width is 15mm, and the expendable bracelet can accommodate wrists up to 20cm; hence, this watch is suitable for men and the women.

Due to its age, this timepiece has not been water-resistant tested.

A hi-quality vintage SS expendable bracelet is provided as part of the deal. It too had undergone a thorough cleaning via ultrasonic immersion and buffed. 

The pictures provided shows the watch in excellent condition (no dents and major scratches), and the movement within squeaky clean and well maintained. It has also been demagnetised to improve parts reliability, minimise wear + tear, and improve accuracy. The only drawback is the lack of documentation and original box. A brand-new EVA pouch is provided instead.

This one-of-a-kind watch will make a beautiful birthday present for that special someone, and its value will appreciate over time. 

Do also bear in mind that it will cost between S$ 180.00 to S$ 200.00 for a proper overhaul, an estimated S$ 80.00 to calibrate (depending on watch condition), and S$ 100.00 to polish including tightening of bracelet links - these costs do not apply when purchasing this timepiece. So, if anyone was to sell such a timepiece at a low price yet claim that it has been serviced, one has to ask what kind of servicing was conducted, if any.

This is a stunning circa 1940s Seiko Seikosha Sub-Seconds in near MINT condition with a beautifully preserved vintage dial, movement, stunning case, and immaculate 14K solid gold indices and hands; so, be unique and own a watch that is almost impossible to source in such condition.