Omega Cocktail watch - information please

Good day to you all,
I was wondering if you could please help me with the below (and attached images)

My good friend mum died recently and she was left her Omega cocktail watch.
She has asked me to try and find out some information about it as she knows very little about it other than she got it brand new a number of years ago.

I have tried to google as much as I can and also tried to get more information on this site
https://www.omegawatches.com/en-gb/vintage-watches
Unfortunately I could not find anything. Googling images I have found similar watches but not an exact match.

I am hoping someone could guide me to more details, such as the collection, year and anything else also such as potential value as they may consider selling it. I have no doubt that it is not authentic, but happy to be told otherwise as I will take direction from you experts.

Please see my notes below:-
No box or Papers
Has gold hallmark (very tiny on clasp) 9 375 and then two images too small to see.
From that I assume 9k, but not sure if gold plated or solid??
Works when wound (but I assume it needs a service)
Face measures 15mm x 10mm
Approx 6mm thick
Back case has no markings
I have not take the back of from fear of scratching it or being able to get it back on (I dont trust the jewellers where I live)
Bracelet is like a Milanese but not.
No damage or scratches that I can see of

Please do let me know if you have any questions or comments.

Thank you.

Thank you so much for the information

Thank you for your help I appreciate it. I am surprised you mentioned that case and bracelet made potentially in uk for uk market, makes sense.
Like I said not sure I brave enough to Open the back. I am very amateur when it comes to this, I have basic tools and change batteries in quartz watches. I suppose fear is not being able to get it back on as wonder if there is the rubber ring inside which may have rotted away with age.