It’s got a very nice case but sadly the dial was refinished — probably during service in the late 40s or early 50s. This logo on the dial was registered in 1942 but in practice we only see it on later watches. Also the crown is a replacement.
Longines had so many gazillion watch references in those days that I would not assume ref 4636 is the only one with a similar looking case.
Here’s one below though- a 32mm gold watch a dealer purchased a couple of years ago on the open market for 400 euros.
Your case is nicer as your lugs are thicker and more defined — his may have been overpolished, but also could be a slightly different reference.
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