Documents trail
To carry on with Engines points trail, point 7 should be the records held by the Squadron Flight Safety Officers throughout the country, who, at least in the case of 664 VGS, will be the person conducting the initial unit investigation into an incident or accident.
As SFSO I reported on one aircraft incident and one aircraft accident, and assisted, after retirement, into a second aircraft accident. On each occasion, as laid down, the following questions were asked and investigated on - What Happened? Were there any injuries? What was the damage? And who or what circumstance caused it to happen?
In each case, statements were taken from all involved, photographs of the damage taken, and explanatory drawings made to amplify written statements. Subsequently, a report was written, complete with my summary as to the cause, and submitted to the Squadron commander who, on each occasion, accepted it and submitted the report to CGS.
So there is another way of confirming the status of all aircraft whilst in squadron service. These reports should not only still be held at squadron level, they should also still be be held at CGS. So, even if all the Aircraft Document Sets were destroyed, (and it is still my contention that those that were destroyed, were destroyed deliberately) There should still be, as stated, records at CGS. If they have coincidentally been destroyed, there should still be the SFSO's copy of the reports generated, signals sent, and results of the unit enquiry. And, of course, the wise person will retain their own copies. I consider myself, in this context, to be wise.