Bottom Casement Window Pivot slider for American Craftsmen Window

The part is difficult to photograph since I need to remove the casement window from its frame. This part is a black nylon part in the bottom corner of the casement that slides on a track for one to remove the window. The top corner is similar. The photo of the shim in the corner of the window demonstrates the need for this part to keep the window in the proper place. I'm attaching proof of the lifetime warranty from PlyGem. They do not have this part and recommended Swissco.