I have a 370 with the sports pack. included. I recently just bought a fairly used clutch/flywheel from a forum member here that he took off from his Nismo after he went TT and upgraded to a different clutch/flywheel.
The condition is indeed pretty decent but the issue is that the clutch looks different from the one being sold at:
Nismo Clutch and Flywheel Combo
I messaged FBNissan, the guy selling that combo, asking if that's the OEM Nismo set and he replied yes.
You'll notice the clutch doesn't have 4 springs around the center, instead it has 8 holes.
The one that was sold to me doesn't have holes, but instead has 4 springs around the center. The seller told me his felt more solid and stiff, compared to the soft and mushy clutch on his friends' regular non-nismo 370's.
I don't think I was duped but I'm wondering now why there seems to be 3 different factory clutches: stock ones on the regular 370, stock ones on the nismo, and another set of nismo clutch/flywheel being sold from the link mentioned above.