These letters were hand drawn and then painted. This is the way most lettering was done before computers, though this job does look amateurish and was probably produced by a beginner.
Drawing letters by hand, and from memory, was a skill that every apprentice letterer learned. A roman letter like this example was usually not based on a typestyle and the word 'font' was unknown in sign shops before computers. The letter styles used by sign painters, called alphabets in the lettering trade, were constructed to be highly readable, especially from a distance. Sign painter alphabets did not slavishly imitate printer's typestyles.as a rule unless it was at the request of an insistent architect or client. Many of the printer's versions of roman letters, such as Times Roman, for example, with its hairline strokes, would have been considered unsuitable for most sign work.
Although extensively used today on computer generated sign work, letter styles like Times are inherently weak and lack visual impact. A sign lettered in all Times Roman has an anemic look. It's too white. Roman letters produced by journeymen sign painters were typically more robust, with thicker thin strokes and serifs. This was not always the case, but it usually was, at least as I remember it. And a good sign painter could modify a roman letter to fit the situation, adjusting stroke and contrast, height, width, and so on, as needed, without yielding the awkward look of a computer font that has been stretched or compressed artificially.
Times Roman looks fine at the small sizes common to print. But then that's what it was designed specifically for—newsprint held at arm's length.
Brad