Vinyl Glazing Bead For Casement Window

This is Charlie. I have three (3) large Crestline casement windows with three panes of glass in each. I need to replace the glass panes since the seals are broken. To do this I need to remove the vinyl glass bead that holds the window in place. These glazing beads are 40 years old and very brittle. I would like to replace them when I replace the window pane. The glazing beads are shown on the attached sketch in red. Please let me know if you have these glazing breads or can get them. If you have any questions please contact me. Thank you and take care.