Here's more pictures where his/ their hair splits on the right at the forehead. I understand this because I have the same problem with mine. Even though my hair wants to go from right to left in the back and on top, it wants to go from left to right in the front.
So, the natural flow, for some of them, was from right to left in the front, regardless of where the part or cowlick was located in the back. It's obvious when his hair does and doesn't want to flow the direction it's been combed.
Here are some pictures during the Wings and Macca eras where his/ their hair does the same thing.
Here are pictures during Beatlemania where his/ their hair did not split, for whatever reason, on the right side at the front hairline.
And during Wings/ Macca. When he has the natural separation from right to left in the front, problem solved. Is this line of scalp what makes it happen?
This looks right, and it looks like many times during Beatlemania his hair would've stayed put on stage during a performance if it had been parted on the right, regardless of where his natural part or cowlick was located in the back.
That leaves this Paul as a really odd-man-out. This part is so low on his head, it makes me wonder if this is the one who was bald, or maybe this is a comb-over? Is there more than one Paul here?
I do not believe these pictures have been doctored, and wouldn't want to use any of them in my research if they were. If anyone does think so, please point out the exact locations with the evidence of tampering.
Two more with an extremely low part on the left side. Does their hair really want to comb in that direction?