We have some windows with 20+ year old blinds, and the valence clips have broken on several of them. The clip mechanism looks a little funky with 3 parts involved: the valence itself (3" across), a 1" valence clip, and the weird plastic insert in the valence that the clip connects to. See images for back and side views.
My questions are: 1) what are the "weird plastic inserts" actually called, and where can I get replacements, and 2) is there a better way to attach the valences?