Awesome site, Kate!
It's in the eyes. Faul's are narrower, beadier. He's probably a reptilian. Those boys at EMI were deep into top secret military projects. Music was just a sideline-until they realized that it was a great method of mass hypnosis.
The real Paul tried to blow the cover on whole thing and had an "accident." Then Faul moved in and took over the band. Yoko was recruited through a Japanese spy ring to get John hooked on heroin and take him out of the picture. She brainwashed him with the silly "peace" initiatives, in the hopes that we'd let our guard down so that the reptilians could conquer us without the threat of nukes.
Faul must have also had some kind of onboard drumming program--which is why he started pestering Ringo about the looseness and swing of his drumming.
Remember, beware the buckyballs . . . .