Broken cranks of casement window in Front Room

Based on your picture, I would start by looking at our 39-022. This has an 11" long arm and rear mounted screw holes. Can you confirm the length of your arm?

If it's 9-1/2" instead, then a better choice would be our 39-139. The only issue is that this has face mounted screws, not rear-mounted. There is a solution around this though. You would just need to use our 33-205 threaded insert by pressing it in with a vise. That will allow you to mount it the same way.