Bruce Smith wrote:
Since freight cars were lettered almost exclusively using stencils during this period, I'm puzzled by your puzzlement. Is it the fact that the stencil gaps were not painted over? There are plenty of examples of that in the freight car fleet, although it certainly wasn't super common. A number of the better decals available have options where the stencil gaps are visible.
I have seen photos of workmen hand-painting to cover the stencil gaps.