Please identify replacement

Hello there. You should be able to replace the thumb lever with the 82-107; however, a thumb lever breaking is often a sign that the mortise lock in the door broke and should be replaced. To test this, try manually 'throwing' the lock with a slotted screwdriver. If it doesn't budge, then you know it's the source of your problems and should be replaced also. See the 82-260. 

Yep! If the mortise lock works okay, then all you should have to replace is the thumb lever with the 82-107. Let me know if you have further questions.