Edo,
I think that you are correct, it's probably a single piece, I get confused on what terminology to use to describe the part..
Gotta find out the width of the center portion of the rotor so that I can figure out what is the difference in width when installing an aftermarket big brake kit.
If the difference is too big I won't be able to fit some wheels that I just got that have a very small offset, since the wider hat width will push out the wheels farther out and closer to the fenders.