I asked my Dad about it, he isn't positive what it is but gave an educated guess.
He seems to think it is one of those items that they hand out when you
"fill" your tank. During the 40's, 50's, and 60's it was common for gas
stations to have different promotional items and gimmicks going on. The
four leaf clover representing safe motoring after leaving with a full
tank.
What was an automotive handout doing at an airport?
Maybe they handed them out to smaller aircraft...
Maybe someone just dropped it...
Maybe they held local auto drag racing at the airport (common back then), mixing avaition fuel with regular fuel was a trick...
But to really find out, contact Gulf.
Well... so much for Dad's words of wisdom with age thing LOL.
Good luck!