Apart from 'strange' handling problems there was the matter of weights where no two aircraft in the squadron of the same type, equipment fit or mod state, weighed the same. I can understand redundant electrical wiring and the like being left in situ in large aircraft but it was equally true for a unit of Bell Sioux which had no room to hide anything! Luckily they all flew much the same, cruising at a breathtaking 70 kts.