Complex sentence: A search for the crash site in 2001 by a local metal detectorist was successful, by finding some of the mounting bolts "cone shaped" that were removed when the remains were dismantled on site.
Split into simpler sentences: A search for the crash site in 2001 by a local using a metal detector was successful. He found some of the mounting bolts "cone shaped" that were removed when the remains had been dismantled on site.