That was a great write up, JetSpeedz :thumbup
This is the area you are drilling to (note the channels are already there ?),between that face and a shoulder on the drive gear is a smaller version of the two rings that go onto the clutch hub first when loading the plates...fwiw.
One thing of note considering this was a low mile 06 clutch was the wear on the damper spring pockets.
I guess it was a space thing but Suzuki have gone away from the design they used to date with twin steel discs to hold the springs.
On this clutch they run the springs one side direct in the alloy of the basket and the wear is quite severe.
I don't know what is going on in there but it seems 160++HP is causing some protest going by those grooves.