I've never replaced a boot in well over a half million miles of maintaining 123 cars.

What I might suggest, however, is finding a 240D in a salvage yard and getting the entire shaft. The reason that I suggest that it comes from a 240D is that the limited torque available allows those shafts to last FOREVER. If you get a shaft from a late turbo 300D, on the other hand, it could easily be worn out.

Good luck,