rotary bolts are replaceable...
Certainly. With enough time and enough money, you can replace every part on the gun. Then you have a refinished and repaired non-original Fox Sterlingworth, and a great deal of any true collector value, because it is a fairly rare ejector pin gun, just went out the window.
A lot of the inexpensive fixes for getting the top lever back to the right on rotary bolt guns involve peening the rib extension. That isn't gunsmithing. It's a crude fix that usually won't last, and often looks like crap.
If money is no object, and going under water isn't an issue, then it can certainly be fixed.