[beepbeep]

That's a easy fix if you can operate the soldering iron. Open the amp and see how they are secured to panel. If they aren't soldered directly to PCB then it's just a case of unscrewing those two bolts and replacing them with generic RCA-connectors of "screw type" and soldering back the coax on them. (theoretically, you could replace them with stock RCA item if you can look up the serial number)

If they are soldered directly on PCB, you can either snip/desolder the legs and then try to mount the generic contacts or just drill two additional holes above them and mount two new RCA's, soldered in parallel to old ones.