It is also worth remembering that in a great British tradition these ariframes were 'hand built'. Although there was a production line, there was minimal machine tooling for the airframe parts.
From memorry this meant that even principal dimension like length and span differed but 20 to 30mm. At a more practical level this meant that panels, hatches etc were alsmost bespoke. So when parts were being robbed it was necessary to find the biggest part and then trim it down to fit. In practice this would mean that any airframe panelling would have to be made from scratch - unless you have access to a variety of airframes!!