OEM Discs are cast in China just like every other major motor manufacturers discs, they're all suffering in the recession.....
OEM stuff's like a cuddle blanket and its good to use for all the right reasons but precision engineered in Germany and hand finished on the thigh of a cuban virgin its not.....
OEM pads are not generally made by ATE although some might be, theres only about 6 ACTUAL pad manufacturers on the planet but the likes of Pagid/Mintex/Textar are all TMD group.
OEM pads with the different end letter show different applications, H at the end of a part number tends to be Ferodo, looking at the part numbers ferodo tends to find its way onto the higher end stuff as well as Galfer. Ferodo OEM stuff is pretty good its the same mix as the ferodo premier range which just about copes fast road.
ATE is also used on OEM, there requirement is so large they have a range of manufacturers all supplying on tender on a week or monthly basis.
Brembo aftermarket stuff is generally made in the EU but again some in Asia