To others reading this - the post was split from another thread so that focus could be provided for this specific application
...... Pictures show a 66 GT350 undergoing a restoration and the radiator markings are being replicated. Would the letters "DSO" and the location number (in this case 26) have been placed on the radiator support for information for the Ford assembly workers?
Firstly the markings shown would have been applied to the bare steel and no primer would have been typically applied in this area. Just a choice the restorer made during the restoration based on the condition of the car and personal choices at the time.
Yes it has been found and documented many times were a worker was assigned to place large visible indicators of the cars interior and exterior colors to the bare body so that while moving down the line other workers could quickly see these details from a distance. This kept them from having to go to and read the buildsheets that would have been attached to the unibody at the time.
If so, why would they need to know where the car is being shipped to?
The additional markings, depending on the plant and year indicate emission system, destination, first rotation number, in some cases options and others details, were also sometimes placed on the radiator support. In this case the DSO applied to the bare steel unibody was an indicator IMHO that certain holes would be omitted, added as well as braces and brackets. Of course none of these had to do with the paint process and were meant for other workers who's station the body would pass through during the first half of the build process.
All of these would have been covered with the engine compartment black in most cases and only become visible over time, sometimes after decades or age, rusting and so on. The wax sometimes leaches outward under the paint marking the later findings much different form the original markings
