"This noise sounds pretty much like a pressure plate held in your hands would sound when shaken. A rattle is heard from the alignment castings (the square nubs on the pressure plate) banging on the square holes of the pressure plate housing."
I think you nailed your problem.
It sounds like you have a rebuilt not new pressure plate. It is hard to get a good rebuilt one. The square ears wear over time and will rattle. I needed to have my parts store order me three, before I got a good one, on one of my jobs. Shake it before you buy it.
