Mtpleasant97

Rebuilding a 65 coupe that I picked up mainly for nostalgia. A 66 was our car when we were first married some 45 years ago. It has been fun to work on but I have come across a issue that I can't figure out. The rear quarter windows have rollers on the control as well as on the window frame. Those on the control are easily replaced but the ones on the window appear to be permanent. The ones on the window frame are nylon and will barely turn. I have spun them with a drill and used every kind of penetrating oil and lube I can think of but to no success. I need help. My questions are (I guess) are: 1. Is it necessary for them to turn. It seems that the should as they run within a track. 2. Is there any way to free them so they will turn easily. 3. If nothing works, is there a way to replace them and where are they available. I will appreciate any and all suggestions. Thanks