Airframe length can vary by something like 200mm between airframes and cockpit height by perhaps 100mm.
Are these figures right? That is utterly unbelievable. My 13 year old who builds model planes, without drawings, would have got the airframe lengths within a few mm. A 200mm variation on an airframe which is GA-sized points to an astonishing Fawlty Towers operation.
Having been peripherally involved in "defence procurement" projects many years ago I have seen some awful wastage go on, but a 200mm variation is beyond the appalling. It's a total micky-take.
Handling qualities are occasionally somewhat variable between aircraft - at one point it was found that about one airframe in 10 would roll inverted if you stalled them in the landing configuration.
I am not suprised. Why did the RAF accept this kind of garbage, for risking servicemens' lives?
Having seen a PC12 close up, I don't think Pilatus build their stuff in this way.