FiSe & GttC,
I would say that it is the wing tip (underside ) of an Irish Seafire note the eliptical wingtip and the orange stripe of the national markings, the orange would have faded in colour by this time. That is an interesting point regarding the ex FAA wing I was never aware of that before and never saw it when I was looking through the Seafire wrecks all that time ago. Makes me feel old!
Tony K