Originally Posted by jpr

I promise you I am actually totally ignorant of that.

The closest I can come was the earlier mention of SHW as the manufacturer of the BMW Motorsport, Porsche, and a few other high-end rotors. But I believe we established, and you concurred that those are drilled ( "I am also agreeing that the aftermarket companies you listed previously do not use that technology, but are machine-drilled." )

So I'm back where I started, still trying to find an actaul real live example of a cast perforated rotor.