A smoker window will not have the vent window in front of it. The track/regulator allows (as you lower the window) the window to drop down at the top front first.
Can to hang a plumb bob from you channels to the section that holds the bottom of the window to see if they are plumb?
Mix of parts? What mix? Is the front roller allowing the window to go down below the track? Is the bottom of the widow, when rolled down, parallel to the floor? Do you have the right piece of glass and is the top cut correctly?
I'm not there so maybe silly questions.


Six volt guy living in a twelve volt world