Help identifying Omega automatic

Hi everyone,

I recently acquired this vintage Omega watch, and I’m hoping the community can help me identify the model and learn more about it. Here are the details:

The dial says "Omega Automatic."
The case appears to be gold (possibly gold-plated or 18k).
It has a simple and elegant design with thin hour markers and no date complication.
I haven’t opened the case back yet to check the reference number or movement.
Based on the design, I believe it could be from the 1950s or 1960s. I’ve attached a photo for reference.

Does anyone recognize this model, or can anyone provide advice on how to narrow it down? Should I have the case back opened to check for more information?

Thanks in advance for your help!

More photos

Thank you for your feedback and advice👍
I took the watch to a professional watchmaker, to get some more details.
It turns out that the watch is an Omega Automatic, produced in the mid-1960s, with a caliber 552 movement. S.n. 161.012.

The second hand is missing and the case is worn, but the movement is actually in a good condidtion.

I’ve attached some new photos showing the watch after being opened and inspected.