Why did AE not refer to it in her records cards she maintained from day 1?
Why did AE not refer to it in her WS dated 14th Aug 1985?
Perhaps because no-one realised the significance of the silencer until September when the police had the blood test results back in September and the police had worked out that Sheila's arms were not long enough to shoot herself with the silencer on.
Why did AE not refer to it in her records cards she maintained from day 1?
Why did AE not refer to it in her WS dated 14th Aug 1985?
Why do the accounts of who saw what and when not only vary from one relative to another but vary from the individual themself at different times?
Memory.
Different people remember different things and get details wrong a month later.
Maybe no-one thought "I must have a thorough look at the silencer because if I don't look at it carefully enough to notice blood and paint, we might get accused of lying and fabricating the silencer".