replace crank covers and screws

It looks like you need a new operator. We'd be happy to help but we would need to see a photo of your operator with the window open so that the arms that move the sash are fully visible.

In your photos, the worm gear appears to have come off with the handle. That part, unfortunately, cannot be repaired or replaced which means you would need a new operator. We can help with the identification but I would need to see a photo of your assembly as requested above.

If you only want the cover, I recommend our 39-154. You can also take your old screws to a local hardware store and they should be able to match them up for you. 

Can you show us a photo of your operator with the window open so that the arms that move the sash are fully visible? We carry a handful of Andersen operators so that will help us narrow down your options. 

Thank you for the additional photo. Our 39-146 and 39-147 Andersen window operators were the first parts to come to mind. Compare our dimensions with yours and see how they match up.