Good gawd no, they look nothing alike. That forehead is the only thing that they have in common and Paul's is much more prominent; making me think he probably had a receding hairline by the time the statue was made.
As for Nicholas, he was a very good looking man, that beard definitely worked for him. Now I realize why I have all of a sudden developed a soft spot for Prince Michael of Kent. He's definitely one of the dead royals that I find handsome.