Maybe I could have picked a better word than "groove"
Although Orchi called it as such. You say it's there
but I can't see it from the picture.
As I said, I am not convinced the case is counterfeit.
I just would also be concerned that the area where the caseback
comes in contact with the case is not worn with a metal to metal
contact scoring. I would also be concerned with the other areas
circled that no longer have the shadows associated with
the original contours and "groove" of the 1675 case. These inconsistencies may, I suppose,
be from being polished off. If so, it seems a strange way
to polish the watch and the top side of the case doesn't show
the sharp edge benefits of an aggressive polish.
Hope this is clear