If you're willing to refinish the shell, gently heat the threaded area then crimp it down slightly so you can drill and retap to stock size.
don't have to close it up a huge amount. saw cut through the slot will open that back up to allow the cable to pass through when finished tapping..
you -may- not need to heat it up, the metal may be malleable enough while cool to bend the slight amount needed.
ken.