Vinyl Jamb Liner Part Replacement

I am looking for a part to fix my vinyl jamb liners. It is a plastic part that wedges inside a vinyl channel. It supports the sash at the bottom via a metal pin, and the part in turn is supported from the top by a metal spring. The part is 2 inches long, 1/2 inch wide, and 1/2 deep. I have included pictures to help identify the part. Your prompt response would be most appreciated. Thanks!