Have you tried MXG gear? I believe it is the Chinese New Year right now, so they might not answer your email til' they come back.
Although I don't own a L'il Native Lockback, I do believe it uses a standard screw pattern. You could make a post asking specifically about the L'il Native lockback screw pattern. I'm sure somebody around here has already replaced their clip. Good Luck.
The sword the body wounds, sharp words the mind.