On some stations Spitfire 'C' wings were converted to 'E' wings, but it required conversion sets from the manufacturing firms and was a lot more of a 'do' than swapping in/out weapons in the 'C' wing. The 'E' wing wasn't universal in that sense.
That said I haven't looked into it too deeply and am willing to be educated.
That said I haven't looked into it too deeply and am willing to be educated.