Certainteed tilt window parts

I'm looking to purchase some Certainteed window replacement parts & need some help in locating two of the three items. I quickly located the finger latch, product code 26-384, on your website. However I could not find the screen holders. It is a small plastic piece that is wedged into the bottom channel outside the window to hold the screen in place. Also at the top of the window is a plastic guide that I need. I have attached some photos for your use. Let me know if you need any further information.