Yeah, they should have been aiming for a younger version of Peter Cushing, not Peter Cushing from ANH.

I had no idea it was a guy in makeup. Something just looked really off about Tarkin's appearance in ROTS, and I chalked it up to typical bad CG, when in reality it is was bad makeup job.

Though I must say, I am impressed with that second photo, though I'd have a hard time believing it would work in motion, but as a still image it looks great. So ultimately, not that it matters with how awful the movie was in general, it is probably still a good idea they limited his appearance to that brief distance shot.

I wonder if his family got money for his likeness being used in the film?