Sorry, I don't know
The MOT chap picked up the phone and ordered it from one of the places they use. They said it would come next day, so I took the car back the following day and left the car with them (I stay there when they do the MOT, I sit in the car when it's up on the lift and waggle the wheel and press the pedals etc when they do the visual).
btw when your mate does the work, take some pics of the discs, I'm intrigued as to why they failed them. Even if they're scored, it shouldn't fail unless the needle wavers on the brake tester. The only thing I can think is that the handbrake was not properly adjusted which made the shoes wear, but even so I wouldn't expect the surface of the drum to be affected. If you mate wants to, then remove the discs too and check the inner surface of the drum ....but those rear discs on the Tourer can be an s o d to remove