Quality Control Issue?

I'm completely going through a 70 Dart GT. When I got it several years ago the former owner told me not to roll down the passenger quarter window because it would tilt forward and it was a real chore to get it back up in place. When I took all the glass out before sending it to the paint shop, I discovered that the back hole to bolt the glass in place had only been drilled half way through at the factory and the window had been held in place with one bolt from the factory. Once the remaining bolt loosened up , the window would move around and get jambed up. Today I replaced the glass with one I had laying around and the car will have a properly functioning window for the first time since 1970...