It makes no difference if the landing gear was up or down if the aircraft was blown to smithereens. They`ll be able to trace the part when they get the serial number.
the surprise is that, after you would have thought fingertip searches of the site for any sort of evidence, this should have turned up more than a decade later. Was anythng else useful missed?
There's a suggestion on the BBC's website that it may have been put there deliberately, rather than fell. And that does make you wonder what that's about. See here.