New user - need help IDing this watch

Greetings! New user here. I'm so glad to have found this forum.

My wife has an older Omega De Ville watch that was given to her many years ago, and we're trying to find information about it, but I've been having trouble doing that. I've looked through a number of online Omega catalogs from the 1970s but have been unable to find this exact watch. I've attached pictures. Here is what info I have so far, from a "For the Purchaser" form that was in the case with the watch:

Metal Ref: BA 811.1115/625
Mov. No. 39870036
Date: 6/25/78

From my own research, I believe that BA means Yellow Gold 18kt; 811 means Lady's Jewellery Bracelet Watch, manual winding without second, and non-water-resistant; 625 is the caliber (don't know what that means). I'm not sure what 1115 signifies, except that it further identifies the specific watch. The face appears to have four groups of what look like diamond material. I noticed what looks like a faint number 8 on the back case. I also read that there may be further information on the inside of the back case.

I found one web site where a user DID make a reference to BA 811.1115. They indicated it was in "Journey" page 418, which I assume refers to the Omega "A Journey Through Time" book.

Can anyone here give me any more information on this watch, including original price? If anyone has the "Journey" book and can look on page 418, I'd appreciate any information from there.

Finally, how does one set the time on and wind this watch? I don't want to damage the watch by not knowing how to do those things properly.

Thanks very much -- Paul

Thank you both very much. This is great info. Any idea how much it would have cost originally (in 1978), and how much it might be worth now? And if she decides to sell it, how and where would be the best way to go about that?

Similar enquiry thread, albeit a decade ago: https://www.watchuseek.com/threads/my-mums-omega-de-ville-help-model-what-is-is-worth.246547/

In that I can see the comment: "That 18K YG ladies De Ville was offered for £845 in the UK in 1977."

Assuming the two pieces are the same (they look to be) and the comment correct, you have an 'approximation' of original costs (Albeit I wouldn't have thought UK prices would have been same as Saudi).

Adjusted for inflation, £845 in 1978 would be £5,091 today. $6,786 US dollars. Given the list prices for todays YG Ladymatic DeVille with diamonds, it was a bargain.