I would imagine that you just need a much firmer embouchure. I played my professor's on monday, and got it to play in tune after I realized that the reed was not the right size for me (brought out a 4, using the original C* on a Mk VI 'nino), and then played on a four.
Make sure the reed isn't too soft, and that you are playing with a firm embouchure!
Sadly, can't tell you about the mouthpiece pitch.