So I looked at your OP, and it really opened my eyes as OPs tend to do. I really appreciate it.
I grabbed the photo I referenced and decided for the first time to try and place/scale it over my painting by using the eye position ( I actually decided to use the photo to make sort of a line table from his face to make sure I had the eye/nose/forehead/mouth placement right, but I never tested for width ) and you are absolutely right. The arm is completely off, it is gigantic! The body needs a serious reduction, the arm needs to be moved over. In terms of the head it needs to width on the right side, but to cut some off on the left side (too much hair on the left side). The ear needs to be brought in, the right cheek (his left) needs some serious bulking.
So yea, I will need to implement all your changes. Could you also help me with the moon by any chance? I really appreciate your help.