I have a very early 175 driver with the smooth grey finish and Jim Lansing decal. It seems the pot metal throat and phase plug have cracked and deteriorated in several places, neither are salvageable. The warped phase plug is pushing on the magnet and causing a gap where the diaphragm plate and body meet. I would really like to repair/restore this driver because it is cosmetically mint and a very early version. My questions are, is it possible to replace both the phase plug & throat with later model 175 parts? Is it possible to remove these parts from a later model 175's without damage? And are there any either options, like using parts from a different model or make? Any help is greatly appreciated.