68 Dart 1/4 window bushing

Hi all! Got my 68 Dart 270 road worthy and am having so much fun driving it! The locks and windows were a little hard to move so I am cleaning and greasing them. The passenger rear window was especially hard. I took it apart and this bushing fell out. I cannot see where it goes. The window is moving great now. It does go all the way down, the drivers side stops about a half inch above the metal. Does anyone recognize this bushing? Are the rear windows supposed to go all the way down or is there an adjustment I'm not seeing? It's working okay, I just dont want to put it back together if I'm going to have an issue down the road from this broken piece being missing. Thanks!!

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