I have what I was told is an old sign from a tire stand that I got from a woman who said her father worked at a Gulf station for many years. Does anyone know anything about these? Is it even authentic? What does the “RO26” even mean?

50F33270-F3B0-481C-8CAC-A4DA90A4A7B1.png (613.65 KB, 303 downloads)
8BB5568F-B522-4FF4-9EC6-4EB19A2CC95F.png (721.02 KB, 261 downloads)
D620A416-5D33-4A6F-8635-B43D96018896.png (668.75 KB, 273 downloads)