The Mystery Card
Cut the postcard into 3 pieces. Where does the 13th card go when the position of the two lower pieces are reversed? The LD letters on the postcard tell us that it was produced by or for L Davenport & Co. See the advertisement from a 1930s Davenport’s catalogue. The white space at the bottom right of the postcard would be used to print the name of the person or company that used the cards for publicity.