GOC pumps were very common and I know they used multiple suppliers for the many pump plates they needed. I am no expert with them, but I can sure tell you that the 'S' and the rest of the font is definitely different than the two real ones for sale here on OldGas. Maybe Gulfiend or someone else will chime in to tell you if this is fake, or a different manufacturer.
But for now, there are two here on OldGas, that you could buy that are real....
Gulf sign link 1and
Gulf sign link 2-Steve