Caradco window part

The lower window sash for three of my Caradco tilt windows (from 1996) will not stay open. It appears that I need to replace the part that the spring attaches to on each side of the windows because a plastic piece has broken off on each of them. The broken piece has a small screw that I believe adjusts the tension to make the window easier or harder to raise. I have taken two photos of the broken piece. I think I need a total of 6 of these to repair the three windows. I can also send a picture of the windows if it would be helpful. I could also use two of the "pins" that keep the screens for these windows in place if you have them.