Flag that tripped Booth

[Rsmyth]

Ed makes a good case for the flag that tripped JWB being the deteriorated flag from the vault and not the one currently on display at Ford's.
On May 15th 1865 Ferguson stated “I heard some halloo (yell) out of the box, “Revenge for the South!” I do not know that it was Booth, though I suppose (guess) it must have been; it was just as he was jumping over the railing. His spur caught in the blue part of the flag that stretched around the box, and, as he went over it tore a piece of the flag, which was dragged half way across the stage on the spur of his right heel.”
His statement that the flag “stretched around the box” may indicate that the flag was draped across the balustrade in front of the President rather than the Treasury Guard Regimental flag that was more than likely hung vertically between the two boxes.
I have a questions for Ed; the only description of this flag is that it was a silk flag. Could you tell if it was another Treasury Guard flag or an American flag. Either way it could have been the 3rd flag in the stand of colors from the Treasury Guard.