Whether hubcaps or Ford Script batteries or whatever, there were no sign painters or nail salon artists or Exacto knives involved in the original factory application of color to Ford cars and parts. Granted, pin stripes on the early models were done by hand, those employees chosen for their steady hands quickly learned their trade to perfection.
You'll notice that in most cases, the painted areas are either in a depression, or a raised surface. For the raised surfaces, a simple rubber ink roller was used, no masking and no touch-up required. For depressed pattern surfaces, paint was applied and any excess was easily swiped off in a single pass. Another method that was often used was a reusable template held tightly to the part, then spray painted. The thing to remember is that in no case was any method employed that required more than a few seconds to complete, meaning that a Restoration today that sports meticulously applied hand painted color accents is deserving of admiration at a Coffee & Cars Meet, but not so on the Judging Field.