For the benefit of those who assume we don’t know what we are talking about, we who say that Paul McCartney is twins, here they are.
Note the differences: The one we know as “Paul” on the left has a slightly longer face, lower ears, wrap-around eyebrows, and eyes that droop far more than “Mike’s” below and on the right. This after plastic surgery. They appear to have been fraternal twins, not identical.
As I understand it now, both Paul and Mike played the part of “Paul” in various gigs up until about 1990, when original Paul retired, and Mike became the permanent Paul.
Of course, a commenter below mentioned the possibility that the guy we now call Paul might have his own double too, a younger man made up to look older. He said a friend of his attending a McCartney concert thought that the drummer was ghosting McCartney’s voice for various songs during the concert. They are squeezing the last drop of blood out of the enterprise.
And keep in mind, Paul could be Mike could be Paul. We have no way of knowing which twin was which and assumed the role of Paul during the early days of the Beatles.