Well Pip, I took your advice. I cut out more of the original headlight area, so I could push the headlights out to the cab corners. No going back now!
Taped off the cab so I'd have a nice straight line to follow, and to keep the cab looking symetrical.
All said and done....
Now it's time to make another set of the headlight surrounds. The next set will be more deeply recessed, so the headlight bezels will be more sunken in then my first attempt! Hopefully I can pull it all together.