Guy,
What about those people that have removed wieght from the dampner and flywheel?
As long as the old damper or flywheel is undamaged, you can always match balance the new pieces. I would spin a core crank with the old item(s) and then add temporary weight to the crank to get the assembly in balance. Then I would replace the damper/flywheel and remove weight from each until the assembly was balanced. Now the new items can be interchanged with the old items on the assembled engine.
Clear as mud?