The print on your sign looks different than mine. Also the border on your sign is different. I know that some came with a rigid frame. I wonder if there were a couple of versions?? Mine has a white piece sticking out top and bottom and had hardware that was made to attach itself to the large "banjo" Texaco signs that were out on the curb. Unfortunately I accidently threw away the instructions and clips to attach it. I am not sure if there were other versions of t his or not. Mine is tin and very "bendy"...I know mine is original as I bought a case of them out of a bulk plant in Montana and the box was printed with the sign information.
Joe, would be interested in seeing the cardboard insert you were referring to.