Replacement Plastic Part

I am looking for the curved keeper part that holds the side opening window latch bar in place on our Accu-Weld Garden Window. The part is about an inch long with two screw holes. It mounts in the window casing area to hold the latch bar up and in place so the window can be locked and unlocked. There are two per side. Both on the right side when looking from inside to outside are broken. Without them the only way we can get the window to latch locked is to go outside and use a screwdriver to hold the latch plate up until the window is closed enough so the plate does not interfere with the window. The attached images shows the curved part that broke off of the flat with the two screw holes. I do not want to open the window so can provide pictures of the other side. It is too difficult to close it again and requires a ladder to reach.