Based on conversations with specialists within the hobby, this may truly be the only surviving example of a Christmas card personally signed by The Big Train.
It was originally given to a neighbor of Walter Johnson's when he lived on his farm in Germantown, MD at the end of his life. The Christmas card was taped many years ago into an original 1st edition (Washington DC version signed by the author) of Roger Treat's juvenile biography "Walter Johnson King of Pitchers". Note the vintage brown tape and discoloration in the book from where the Christmas card has resided for perhaps over 60 years... The signature is in blue steel-tipped fountain pen.
It's been suggested to me that I carefully remove the card from the book, but I think it's pretty cool the way it is. I'm not a big fan of changing something that's remained intact for so many years.
Any thoughts from fellow members on this topic would be appreciated!