I like Mick's autograph, but I'm not sure about Paul's. I have some issues with the P and the l. But that could be related to the squeezed space he was trying to sign in.
Both are authentic, IMO.
For Paul's, I have seen the P like that many times, and think it all looks good overall, certainly his standard sloppy last name that he does now (if he does it at all). And the Mick is great.