This is a picture of the guide that is no longer available it's called a face guide for a single hung window.
That is the screw that attaches the face guide to the sash.
I have 400 of these windows.
Good luck trying to find it let me know.
Paul from SWISCO responded:
March 13, 2017
The closest matches we have are our 67-015 and 67-002. That said, I cannot guarantee either will work. Compare them to what you have now to confirm.