I am a little bit confused here. The Sea Vixen is a registered civilian aircraft (G-CVIX) and is not owned by the Royal Navy. It therefore must have been insured by a civilian insurance company and not by the MOD.
Surely the insurers have a duty to restore the aircraft to its original state, reach a settlement with the owners or scrap it and allow the owners to buy back the wreckage?
(I have owned, operated and insured several civilian aircraft in my time).