As I was going through some cards in my collection this last weekend, I came across this E121 Series of 80 card of W.L. Gardner (SGC 50) and I upon closer inspection noticed that the card has a ghost image on the reverse.
Looking under a magnifying glass I'm surprised to see a that the image is a ghost of a E120 Tris Speaker. It's kind of hard to see in the scan but the coloration is from the E120 American League cards and I can make out some of the more ornate framework around the oval bottom.
Has anyone ever seen different issue ghosts before?