It’s important to note that they are two kinds of closures on these clasps, the ones that pinch in the sides and have the open front and the ones with the hooded fronts that clamp the bar on under the omega logo. If you know which one you have you can compare and find a match.
Here’s an example of one- never dealt with this seller and don’t know if it’s the same as yours but compare
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/222923439786Click to expand...