Ken & Gregg,
The two sources I mentioned are a thread on this message board dated July 6, 2007 and the book "Law's Alabama Brigade in the War Between the States" by Morris Penny and Gary Laine. I would have to go back and check the page numbers and notes to be more specific, but, in the book, they indicate that at Appomattox, the flag bearer took the flag from its staff and concealed it under his uniform and had the flag buried with him when he died. It's altogether possible that this may have been the flag the regiment carried at Gettysburg. That's why I asked the question I did. If there is some kind of record that the 15th recieved a 4th bunting in the spring of '64, then they may have been referencing two different flags and two different flag bearers.