Vintage Omega 1972 Rare or Franken or What?

Please help me identify this watch. My intent is to clean it up a bit and have serviced for my personal use. BTW, as is, it keeps darn good time given its condition. This is a Estate Sale purchase. The watch's owner was a doctor who worked internationally. This is relevent only from the perspective that I dont think this is anything built to deceive.

First off, know that I am a relative novice. That said, I have done a fair amount of self education and research. thanks to Omega Forums, and Omega and privately generated guides, I believe I know the various movement, seriel numbers, case reference, etc.

Now, on the surface, it apears that this is a 1972 Omega Geneve Automatic Ref 166.0117 (Caliber 1020). The lack of confidence I have in that identification is this:
1. Ref # 166.0117 being on the case back could have come from a replacement case back at some point in its history.
2. Every "Geneve" ive seen has Geneve on the dial. I am aware that there were occasions where Omega issued watches with no collection designation on the dial, but I thought i understood those to be mostly Seamasters.
3. Note that the crown does not apear to be original

I guess the essence of my question is what collection does this belong to? Geneve, Seamaster, dont think it is Constellation but cant be certain, or what? Those Omegas with collection name on the dial, how are they identified/classified ?

Let the opinions fly!

While the photo is not great, I would say this is an authentic Omega Ref 166.0117. When you get it serviced you can get an Omega crown put on. Given that this belonged to a doctor who worked internationally, this is a watch that could tell a lot of stories, I believe. Personally, I would remove the old bracelet and once serviced, put it on a quality tan coloured leather strap.

Poor pictures, but the movement looks to be ok. better pics needed.

Thank you all. And totally will get the crown and new strap. Here is new, better picture, It is rough shape. But seems to be keeping good time.

Nice looking watch 👎. Have seen these with or without Geneve branding, no issue IMO. Have it serviced, correct signed crown installed, and stick it on a nice brown leather strap and you’re good to go.