Contacting Kershaw is the best decision, I think.
The next (costly) idea would be to have a craftsman replace the scales professionally. You could go with a dark material that would not only honor the original but maybe be more durable as well.
If you were going to do it yourself (the way my late grandfather would have preferred), Super Glue or epoxy mixed with a bit of charcoal dust has been an effective patching method to hide the cracks on Buffalo horn handles. Flexing it a bit then working it in, wiping off the excess, and buffing it a bit before it fully cures seems to be effective. Not invisible but the end result looks clean.
Best of luck.