I have an Omega f300 Cone Day/Date with a bracelet. Unfortunately, the bracelet is unable to be resized down to my very small wrist size.
Removing the bracelet still doesn't work as the spring bar area is unorthodox: it is a 9mm spring bar width! Furthermore, even a custom leather strap won't work because there isn't enough clearance for a leather strap as the clearance between the spring bar and the case of the watch is minimal: merely enough for a thin metal tube of the bracelet to sit. Leather will not be able to be made so thinly and still function as a strap to hold up a watch.
The issue is this:
there are other ring attachments that Omega has made for this watch, and that other ring attachments attaches to bracelets with a more standard spring bar width (17mm). This type of ring for bracelet attachment has sufficient clearance for leather, as many others have done so.
please see the following pictures. the first few are my watch with the 9mm spring bar width.
the other pictures are from a UK site showing pictures of how they used a black leather strap successfully and attractively for this model.
May i ask if anyone might have the Cone and might have such bracelet attachment rings? or maybe a donor watch that doesn't work but has the bracelet attachment ring which they are willing to sell?