NutLoose did all the right things in certifying the writing-off of an aircraft.
All records for UK-based aircraft still need to be retained, by operating companies, for 2 years after the aircraft has been written-off or permanently withdrawn from service.
The Part 145 MRO is required to keep all records of its work for 2 years after closure of the workpack.
However, I have known at least one small company that bought wrecks, worldwide, had them delivered by Pallets and ISO containers, and set about refurbishing them to very high specifications and customised to buyers requests. The end results were quite nice indeed and all done in full co-operation and approval of the national authority surveyors.
I believe it was a quite lucrative business too!