If anyone has this specific heat sink and wants to get rid of it, PLEASE let me know!

Do not even bother....
A magnesium head does not give enough cooling, for sure in hot weather you will get tunings issues.

Friend of mine has been using it in his Ninja for the past 4 races with no tuning issues.

Then the piston must have a tight fit....

2 years ago it was hot for a short time. Sirio, GRP/Ninja, RB, OS and some more had these magnesium heads, where are they today? Many users mentioned higher temperatures and tunings issues as I have seen it within our nationals.
All manufacturers are drilling out aluminium heads to save weight and still have enough cooling.