[Leon]

I am doing some research on Barney Dreyfuss's rookie card. I see OldCardboard has it listed as the D322, 1910 card. They also have a few newer cards I wouldn't consider. I saw a postcard of him that is a year earlier. I wonder how many earlier postcards, before 1910, exist of him? Even though a postcard might not be considered "a" rookie card I am just getting some thoughts. Thanks in advance.....