I don’t know what brand of Vibration dampener you are using but most quality dampeners will dampen without putting it on 100% of the area. What I mean is you should be able to place only a small amount of the dampener on the inside of the door and achieve the results you want. I saw a demonstration of vibration dampening once. They had two cymbals, one with a one inch square piece of material on it and the other with nothing. There was an incredible difference in the dampening with only the one inch square piece.
