You might know this, but the rear sight is not just an interchangeable back plate, it's part of the whole breech assembly. If I desperately wanted a new rear sight, I'd opt instead to take the slide to a creative machinist to see if he could figure out a way to mill a dovetail slot somewhere. If not, I'd wait--my bet is that Caracal is going to come up with a "fix" pretty soon. If you want to make inroads into custom custom Caracal parts right now, you might want to start with offering a selection of front sights--they're easily interchangeable and I'd pay for a fiber optic or tritium front sight that was slightly narrower than the stock sight.
I would be interested in a front fiber optic sight but yes the rear sight is a whole different story....
