Hello,
If you are looking to replace the entire casement operator, I'll need to see a photo of the actual operator. I would specifically need to see a photo of the body of the operator as well as the arm(s) and how the operator connects to the bottom of the swinging sash. Otherwise, the cover can be replaced with the 39-107 Truth Hardware Operator Cover and the crank can be replaced with the 39-102 T Handle.
Your casement window lock looks similar in design to either the 38-075 Truth Hardware Low Profile Sash Lock (compatible with the 38-089 Casement Window Keeper) or the 38-170 Casement Lock With 1/2" Post. To determine which of these is the correct replacement for your hardware, you'll need to carefully review and compare the dimensions and design.
The worm gear from your operator has become dislodged, so the entire operator will need to be replaced. Unfortunately, that part of the operator isn't something that can be repaired.
To identify the correct replacement, I'll need to see a photo of the entire operator. In addition to the photos of the body, I'll also need to see a photo of the arm(s) and how the operator attaches to the bottom of the swinging window sash.
Please don't hesitate to reach out with any questions.