The AAIB said all one needs to know about serviceability.
They were unable to test key components because there was no APs or test equipment available. A repair is not complete until verified.
This failure to provide up to date APs and TE is exactly what QinetiQ reported in their Nimrod report some years later.
The policy decision not to maintain APs and test facilities was made in 1991 by AMSO. As you say Fitter 2, we look forward to the day he and his senior staffs are asked to explain themselves. He seems fond of speaking about ZD576, as he writes to the newspapers about his first hand knowledge of the cause. Of course it's "al cock" and bull.