1965 Dodge Dart 270 wagon

Seems the way to go Don!
This is how the profile on the outside weatherstrip moulding on the tailgate. The procedure to mount the rear glass is to put the bracket for the glass inside the tailgate and add the rubber moulding. Then it's just to drop the glass inside and secure is with the three Phillips screws. Simple as that!

Got a pic of what you are describing for the weatherstrip?