I think you can get it back. When you go back to the thread and start typing a new message, you'll see an option named 'Restore auto-backed up post'. It should appear just above the 'Show your signature' check box. CLick and, and it should be back.
I have the boxset that this track was taken from - this was the first take of room full of mirrors, complete improv from all three, you can hear noel making a bassline as the song goes by, just incredible musicianship. A sad loss for the world.
