I'm looking at some 999s fairings to replace the lower left fairing (melted from the exhaust heat) Am i correct in thinking that any fairing from an other 999s fill fit my 999s 05 model?
No. 03-04 and 05-06 are different. None of the 3 parts (top bottom and air deflector) are interchangable. You want the parts with C at end of part number. To identify them visually look at the deflector mounts. The earlier type have a stick out bit.