Bill asked me if I could solve a problem for him. When he visited the Molsheim factory he also purchased a set of new differential gears, to include: Crownwheel and pinion, planets and sungears. He had given the crown wheel and pinion to Guest Gears in Walsall to run them on their pairing rig. They could not achieve a suitable pattern. Taking a look at the original one from the car it had tip relief on the tip of the teeth, the one from Molsheim had zero relief. After grinding the relief onto the teeth and rolling by hand the difference was immeasurable as can be seen by the picture with the paint on. It did indeed pattern up fine when Michael did the final assembly.