Alan, the only thing I would do is fit the doors to the cab and gap them well before welding anything.....
I might even be tempted to tack weld the door to the cab,due to the fact you're disturbing the lower hinge.
Once you're happy with the panel fit and have tacked the repair panels in,remove the doors to finish welding.
It's the only advice I can think of as you obviously know what you're doing judging by your build pics.
Just remember the old adage, measure twice...cut once!
If you approach this as efficiently as you did the roof,I'm sure you'll be fine.
Good luck.
