Double hung wood sash window repair

I need to identify the parts to replace the "plastic" clips that hold the bottom of the sash balance springs. These windows were manufactured in the mid 80's and have the vinyl channels on the sides.I would also like to find the vinyl stop that holds the double panes in the sash. I need to replace one of the panes and feel fairly confident that the stop will probably break during removal.

Picture 2 shows the bottom of the clip installed. Picture 3 shows the entire clip sitting as it was when I opened the window