1968 Mustang Coupe - Wheel Vibration Shakes Whole Car.

So my brake drums were way way way out of spec and the other day I was driving and the outside of the band broke loose frome the plate on the drum. Anyways I went and bought new drums and were replacing them.

My question now is why does it vibrate? I lined up the hub, and pressed the studs in. Now the car shakes violently whenever the brakes are applied. The wheel bearings are still good. Does the drum from the factory need to be turned? Could the old hub from 1968 be warped or could I clean up the hub surface?

Any ideas would be appreciated. The peadal moves up and down like the drum is out of round.