As this thread has reached an almost philosophical plateau, let me make a last observation based on Old Iron's comments. Some of us have been collecting so long that some items pre-date reproduction anything. I have some Dr. Pepper signs from a warehouse clean out in 1977 that are dead, solid, NOS, mint. I found them in the shipping crates. I can say the same for a couple of my globes and oil signs- bulk plant treasures from long ago. When someone who hasn't seen my stuff - old line collector or a new one - a often get the 'must be a repop, it's too good' reaction.
A collector I know has two Mobil pump plates, made by the same manufacturer (and marked by that company) at obviously different times as the Pegasus logos do not match. Repops? Absolutely not. Just dead solid perfect pieces. And isn't that what we all want?
I've seen the Gulf Supreme sign in question. It is very, very nice and I think if you could see it with its heavy shelving, edge and slight field chips, mounting holes, and the cripsness of the artwork, you'd have to agree that if it is indeed a reproduction, it's one of the best ones ever done.
I was merely advising caution before labeling a dealer as a crook and an item as "obviously fake." One would hope fairness and circumspection would be in order as all comments will theoretically be here forever.
And, yes, let's have a beer . . . .