When did station name signs start being branded?
I picture more or less plain lettering in one color on some other color, without any RR insignia, for the old signs. Railroad names and insignia I picture being separate, like Boston Terminal Company on hte facade of South Station, or Illinois Central Railroad on the platform-facing wall at Effingham, IL (a former union station with NYC/Big Four), or Boston and Maine on the old Garden, all those Overland Route shields on old UP stations, etc.
Tangent, more suited to railroads in other media: the newest Little Women
movie used an actual station from some other town, but they put "Concord Station" or some such on the street side
of the building, where I think it's more likely that the sign would have said "Fitchburg Railroad"; ignorance, or a realization that nearly all moveigoers would have said "Fitchburg???"?