Omega Seamaster Ref.136.005 Cal.610 17 Jewels Manual Wind, Overhauled, Manufactured in 1964 Omega

This is a 1964 Seamaster "Ref. 136.005".

It is powered by the manual-winding Caliber 610 with date, which was developed in the late 1950s.
It is the manual-winding version (without the automatic winding mechanism) of the renowned masterpiece Omega Cal. 560 series, and features a slim profile made possible by the absence of a rotor.
The regulator used for fine-tuning precision features a beautiful, classic adjustment mechanism known as a swan neck.
This is a detail specific to the early Cal. 560 series manual-winding movements, as it was simplified in later generations (such as the Cal. 611 and Cal. 613).

The case and case back are made of stainless steel, and the case back features a screw-back construction engraved with the Seamaster’s iconic seahorse mark.

The width is approximately 33.4mm (excluding the crown), which is slightly small, but because the vertical length including the lugs is a solid 40.6mm, it feels more substantial and well-balanced on the wrist than the numbers suggest.
It is a great fit for those with thinner wrists, as well as those looking for a vintage watch with a clean, understated size that slips easily under a shirt cuff.

The dial has aged uniformly to a champagne color and features fine spots, characteristic of the unique look of an antique timepiece.
The crystal is the original Omega acrylic crystal, featuring the Omega symbol in the center.
The crown is also the original Omega version featuring the Ω symbol, and both winding and time-setting operations are smooth.

Condition

This watch has been overhauled.
The strap has been replaced with a new leather strap by Morellato, so you can wear it with comfort.
While the dial shows discoloration and small spots due to aging, it has acquired the pleasant character expected of an antique.
There are minor scratches on the case and exterior from use, but there is no significant damage that would detract from its atmosphere.

As this is a vintage watch, it is not waterproof. Do not wear it in high-moisture environments (such as on rainy days, while washing your face, or on hot, sweaty days).
Additionally, as it is a precision instrument, please be very careful to avoid strong impacts such as drops, as well as magnetism (smartphones, PCs, speakers, magnetic bag clasps, etc.).

How to operate Caliber 610

Pulling the crown: Insert a fingernail between the case and the crown and pull it out gently.

Pulling the crown too forcefully may cause it to come off. Please pull gently.
To prevent bending the crown, please remove the watch from your wrist before operating.
Operating with care reduces the strain on the crown.

Manual winding: With the crown in the normal position, rotate upwards.

To wind the mainspring, rotate the crown upwards slowly and carefully.
Winding feels light at first, but becomes heavier as the spring approaches full tension. Please be careful, as forcing it past the point of resistance will break the mainspring.

Setting the time: Pull the crown out and rotate downwards.

The second hand does not stop (there is no hacking function).

Quick-setting the date: Pull the crown out and toggle between "9 PM and 12:10 AM".

1) Move the hands forward until 12 o'clock.
If the date changes, it is midnight. If it does not, it is noon.

2) Move the hands forward to 12:10 AM to advance the date. Then, turn the hands back to 9 PM.

3) Advance the hands to 12:10 AM again.
Confirm that the date has advanced by one day.

By repeating this process, you can quick-set the date one day at a time.
Please operate slowly to reduce the strain on the movement.