Dennis, I have been painting for over 25 years and I still have to redo stuff every once in a while. My father has been a painter all of his life and I still seek advice from him. My number is listed in my signature and if you have any questions I'll see if I can help.
It's great that you are keeping at it until you get it. Patience is important and sometimes we just get in a hurry and screw things up....
I would suggest getting all the practice in on the panels that bolt on. Even on the underside of the hood, before the top. Get used to it before the cab.