The isolated score is courtesy of Editdroid. I don't hear the sail barge music in it (I expected something sourced from one of the Making Of specials), but there is an instrumental version of Lapti Nek which took me by surprise. Don't know source on that.
I've never heard an instrumental version either! Have you since found where is originated from? I wonder if it comes from any these
Whilst on the subject of Lapti Nek, does anyone know anymore details on this item