As for the bearings Im not really sure what generation supercharger Holden uses but the bearings down here are sealed in the case and only a minnimal material breaks away to release the bearing ,there are only two reasons I can think of why these are sealed
1 It is done as a parts sales excersise at $900 + for a set of rotors you see what I mean also it strange other manafactures have key ways for rotor aligment aswell as there bearings are removable and use very similer designs
or
2 It is done to stop them from moving forward ,I have checked this out and cant see how they would move as the rotor holds them into place tightly and the outer bearing seat is tight but having said that you dont need a real lot of pressure to get them in ,so just to be on the safe side I locktited them but if you are really worried about it, you can do take the bearing block to an engineer get this done see picture
I havent done this several engineers and bearing suppliers assured me they wouldnt move once locktited in and I will have a challenge if I ever had to get them out again but they still will be removable