Bases on this picture of a trunk lid being made/assembled at AO Smith the second (ground wire) was in place along with the hot wire for the light, when the trunk lid was painted the exterior color
Looked and could not find a picture from an original car showing the paint on that specific wire to share but the original picture sure seems to suggest the pattern would be similar between the two wires.
What the picture shows it the two ends of both wires where they will exit the trunk lid to be attached later to the car's wiring loom being held in place to the bottom of the inner liner of the 69 Shelby fastback trunk lid, as that section is being lowered onto the outer skin
Hope this helps