Hi nice picture and you obviously have the right kit for the measuring, I used to have a friend that was an instructor for the Nigel Mansell racing school at Sneterton so I had the privilege of spending a lot of weekends there and learnt a lot, what you have is classic wear caused by basically what is a track car set up on a road car, this system is essential on high performance road cars such as Ferrari etc that are running over 400bhp, you could have the discs skimmed but I think you would achieve bottom limit before they cleaned up, my theory for what its worth is if I used genuine discs and pads on my A6 they never lasted that long but the reverse is if I bought ATE high carbon discs and used Brembo pads I got at least a third more wear out of the discs and pads and on a cab thats not bad going, I think on later vehicle Audi have probably done the cost cutting thing with the carbon content for the discs, lets face it they would do this just save money.
Steve.