That doesn't really allay my concerns HB!
I can't explain it any better Snow, if the Police assumed that Sheila had shot and killed everyone and then killed herself, why look for a silencer that hadn't been used, they naturally thought a shot person would hardly shoot themselves dead and go and put a silencer away from the scene? It wasn't just the silencer they left in the den, they also left other Weapons and ammunition, why leave them?
The plan worked, the scene was set to make it look like the silencer wasn't used both beforehand when Bamber went to shoot rabbits and after when it was staged on Sheila, and the Police fell for it?
You can only blame the senior investigating Officer who read the Scene as Bamber intended for it to be read, he read it that Sheila killed everyone and then killed herself. Even the Judge said "the scene of crimes examination left a lot to be desired" [perfuncory in other words] it was Completly lacking in care and thoroughness.
Stan and Taff, both visited Bamber on the 9th, it was just to go through his previous questioning, and that is probably where the silencer issue was brought up again, but originally it was brought up with Bamber on the 7th, if TAFF as you put it was suspicious of the silencer then, he would have ordered someone to search for it?
Stan was handed the silencer because i think TAFF was away [i think iv'e read he was on a course for a couple of days], if TAFF wasn't away, it's likely he would have been handed the Silencer.