Thought I would add some pictures of this details since I didn't find that it had already been covered using the search feature. If it has I'll just merge if found.
As we've discussed before, the interior paint that was applied to the unibody during the paint process was applied before the exterior paint. To protect the painted surfaces a mask was used to protect these areas from the body paint application. At Dearborn this year it appears that similar masks were also used on some deluxe interior cars but the mask was different in shape. We'll cover that in another thread focused on deluxe interior 70 Dearborn details
- The interior paint was applied first and did not follow the weather-strip "line" along the bottom of the door. Even on deluxe interior cars there was a mask used for the interior surface that still left a shadow from it on the bottom of the door bottom surface but will save pictures of that one for another thread on deluxe interior 70's Dearborn or NJ. There have been some recorded examples on deluxe cars were the wrong mask was used or not used because of when they were built.
- Application of both interior color then exterior color often didn't coat the full bottom of the door edge likely due to the height, age and effort of the each of those two painters
Top example you can see the interior and exterior colors and the line the tape/mask left. And the bottom that shows where the mask was installed though the interior painter never made an effort to bend over far enough to apply any paint there so just bare metal.
- The edge of the mask used at the back edge (door jamb) of the door was often not a level line but very often the edge created was at an angle
Typical standard verses deluxe difference
Examples of some of the tape/mask edge at the rear of the door
