Replacement weather seal for basement hopper windows

These windows are 41 years old, and the original weather seal material is very worn/deteriorated. Size looks like 3/16" x 3/16" Also, it does not have a plastic backing, but appears to be a woven material, which is somewhat flexible.

Notice that only some of the channels on the windows have an opening to slide weather seal into, while other areas seem to require some sort of "press in" style material. Thanks for your help!