What is the reference? Will be on the inside of the caseback. Looks like a C-case from the late 60's or early 70's. The patina on the dial and some of the indices might make it likely that they started life together. That looks a little like rust on the 6 o'clock marker, I'd be wary of possible moisture ingress. Edit: I see reference number is in the title. And only three Heinekens in, too.
It's actually reference 168.0027. https://www.omegawatches.com/planet-omega/heritage/vintage-details/15576/
For me, the hands look like from an earlier ref. But I leave this to the experts. Cal 564 I personally like a lot ( if it's included)
about the hands (hours-minutes) they told me they are original of this model, but I have the impression that the clock is fitted with various different pieces
I don't understand. I am talking about the physical watchcase. Corrosion, awful finish. That stuff can't be fixed. But there are lots of good parts in the watch that can be used to fix another watch with a better case.
It is not that bad. If you like, you can have it serviced, change the gasket and don't wear it near water.