What Kevin said is accurate. I reviewed many photo's of "original" pictures of trucks interiors door opening and cabs . Here's a couple pictures of my restoration , you can see the interior color on the cab starts where the outside metal wraps to the inside. Doors, similar. I guess you'd call it a transition. I can tell you that the masking was fun. You should be able to "save" the pics , open them and then zoom the pics and see what I'm attempting to convey.
I am very impressed with the job you have done. I just wish the ones with the taskforce trucks would strive to do what you have done. I'd like to see more photos of your restoration.
Is that a single stage paint and what brand?