What is the build date of the car. On the front side tab 068 or 68 would be the Julian day of the year and on the back side should have 9078 around the same place you found the 068. The master cylinder should be 5460346 casted on the side of it an if it has KC on the front tab I would say it is wrong. It should be the same as Camaro which is WT. Both my J52 cars didn't have a code on the master cylinder.
Here is my original booster Julian date of 128 for an 06B car
Casting on master cylinder.
