Do you sell this milgard door hardware?

Thanks for posting. Yes, when the mortise lock fails it often causes the thumb lever to snap. I suspect the mortise lock is our 82-238, except instead of using a face plate it is encased by the entire trim along the door. You'll need to see if you can extract the trim to replace the lock. Make sure the dimensions of the 82-238 match what you have.

Alternate view of 82-238

For a new thumb lever, see our 82-240. Let me know if you have any questions.