40s vintage watch mens Omega Ref 3879 /1 hand wind Cal. R17.8

Case:
o All in stainless steel curved inside ref. 3879/1 - PATENT +
o Fine condition with strong geometry
o 23mm without crown / 37mm lug to lug / 8mm thickness / 18mm lug width
o Plexiglass in good condition 

Movement:
o Mechanical manual wind Omega 1 cal R17.8 - serviced by watchmaker on May 2026
(movement was disassembled, washed, lubricated) - photo timegrapher

Dial & Hands:
o It was repainted in the past; between the logo and the 12 o'clock position there is a shadow of the logo and the omega letters, but it is only clearly visible with a magnifying glass or good quality photos.

Bracelet Material:
o New croco black  leather flat 18mm with generic chromed  buckle

Conclusion / Condition:
A very rare piece from the 1940s, extremely elegant on the wrist.

please see photos as they are part of the description.
No  box or papers, no water proof test, sold as is, any question feel free for ask...
Keep in mind that it is a vintage watch, it is normal to be 1/2 minute early or late
wrist-treasure