Tragic Rug,
In your original post (before your editing) you said that you were doing a dissertation. What level and what degree? Post-grad? And what weight/hours have been given to this dissertation? Is it equivalent to a one semester subject or what?
You can construct your own payload range and takeoff length charts for the aircraft, to a reasonable standard. Not for operations, but sufficient for a dissertation. Based on the data from Jane's, and some fundamentals of aircraft operation. And this sort of construction from fundamental principles is often a required part of any dissertation.