BOOSTN,
r u talking about the 1/4 glass excess movement from front to back of car? if so what you need to do is drill and tap the little plastic roller supports and screw on a 25mm nylon/ball bearing house screen door roller available from BBC hardware.
If its the front windows then you can adjust the bailey channels. I didn't know they had rubbers- I just used lots of grease.
- still, ask Duncan in the club, he works for Spectrum (ld Peter Jackson Rubber) rubber at Dunheved, Sydney for the rubbers- and all rubber for cars for that.