6' Hard Plastic Texaco Sign

I have two of these signs, they are six feet in diameter, hard plastic. They still have the metal ring around them. There was a light behind them to illuminate them. They came off a service station in Rhode Island when it closes in the late 70's early 80's. Has anyone every seen any more of these, I have not been able find them anywhere? I have some people interested in buying them but no market to set a price.