Place to buy rollers for side glass

Does anyone know who sells the plastic rollers for the side glass? My ever snowballing headliner replacement on the 70 Dart has turned into painting all interior trim, adding insulation under the carpet, replacing some foam in the drivers side seat and yesterday I noticed a broken roller on the quarter glass! Fun Fun!! Thankfully the window still goes up and down. were trying to get ready for a show in two weeks so I might wait to repair the window. I found half of it so hopefully I can match it.