Definitely a 26.5 SOB Inside. I don't know for sure the the ref of this model with a 26.5 in 35mm. One of mine says hello :
The same case and size existed with 23.4SC Inside Under ref CK2015 :
One of mine says hello :
At this period, the same case in same size had the same ref whatever the caliber Inside was so I suppose your Watch is a CK2015-26.5.
The same case design existed also in gold with a smaller 30mm diameter under ref CK2069 and in 28.5mm diameter ref CK2071
Click to expand...