Can anyone confirm if this is a frankenwatch? From my limited knowledge SC refers to a center seconds hand. But this one has a subseconds instead.

 

Yes it is.

 

What should be the right ck number?

 

The watch is fine. That is a dual reference case-back, both for the ref 2888 (sub-seconds) and the 2864 SC.

https://www.omegawatches.com/en-us/watch-omega-other-omega-dw-2888

 

Both of those references use rotor wind movements, 491 and 501 respectively.

Note the case has two notches for movement clamps.

 

Yes, indeed. I was so focused on the sweep vs. sub-seconds that I didn't even look at the movement. That's funny.

 

Omega has dual references for cases? That makes it all the more confusing.

 

2846 - 2848 SC is one I see pretty often.

 

you guys are next level, I wish I had come here years ago!