isonprize sent me this information about the train from a train buff friend of hers.
"Built by Pullman Standard in 1930, as a 10-section lounge car for the Southern Railway and named General Polk. The car operated on the Crescent between New and New Orleans. Purchased by the Georgia Railroad in 1949, the car was rebuilt to the office car configuration it has today and given the number 300. The Georgia 300 made regular trips to the Masters golf tournament and, occasionally, the Kentucky Derby, hosting Georgia governors and other dignitaries. Declared surplus with the merger of the Georgia Railroad and the Family Lines, the car was acquired by the current owner in 1985. It has been rebuilt and has hosted Presidents Carter, George H.W. Bush, and Clinton. The car is based in Orange Park, Florida, and is owned by Jack Heard."