Can't seem to find lady Omega model

Hi

i'm new to the forum and to be honest also to the Omega watch world.
I've just purchased an vintige ladys watch as a present for my girlfriend.

And as a gift it's much more interesting with a bit of history or some bits of information about it so i started to search for them on the internet.... and here things get interesting. 😀

I've bought it on Ebay from a seller from UK.

The watch looks original Omega i would say from aroud 1967 (based on internet info) or so but i can't seem to find the right matching watch face.

The nubers stamped on the back cower are: 511.021
The only match i have been able to find on an Omega site is the watch from 1965 with a number: 511.0002. It looks the same but has a different face. To my understanding both watches have a solid 18k gold case. The mechanism on the one on Omega site is 620 and mine is 625.
https://www.omegawatches.com/watch-omega-other-omega-ba-511-0002

I will be immensly happy if someone has some knowlage on the matter and si willing to share it with me.
I hope the photos are in some help too. If there is some detail i've left out please let me know and i will add it.

Best regards
Rok

511.021 is the case reference number, meaning that this case could very well have had different dials (some of which might not be in the Omega Database). The serial number on the movement is in the 38 millions, meaning that the movement can be dated to 1974.

To add, the 625 was the next generation of the 620

Lettering in mechanism is very bad....
Are you all sure its a genuine omega?

Compared to this 511.021 for example with cal 620
https://www.catawiki.com/l/34148815-omega-no-reserve-price-511-021-women-1980-1989

or this cal 625?
https://www.catawiki.com/l/34148815-omega-no-reserve-price-511-021-women-1980-1989

Do you by "mechanism" mean the movement. I personally think it looks ok, and maybe it is just bad lighting. There is, however, something about the dial but I can't quite seem to put a finger on it. Maybe it is just me..

Also, it seems that the crystal that have been fitted on the watch has a tension that is slightly too big, covering the "swiss made". This is quite common with replacement crystals though.

Yes i meant movement.

A on OMEGA for example is bigger..

In general it seems like the lettering was handmade....

Thank you for all replies. You've really made my day with a lot of grate information and the gift will be even better now. 😀