Lock arm latch cover for Marvin Casement Window

We have a Marvin Casement Window (2 panes) with a lock that latches using a small arm covered by a plastic case that breaks very ealily. We need replacement for this plastic case.

3 images attached: one showing the latch mechanism and a broken cover, one showing an intact cover, and one showing the ID tag on the window (with its product ID I think)