It remains possible - that the silencer (DRB/1) was found in the gun cupboard on 10th September 1985, and that Robert Boutflour made a statement to the police on that date, mentioning its find, but that his son, David Boutflour, did not contact the police until the following day (11th September 1985), to tell them that he had found the silencer in the gun cupboard at whf...
OK. I just asked you about that, but you answered before I posted it. 
-------------------
I am searching my files to locate the Robert Boutflour statement, dated, 10th September 1985, but in view of its absence as I speak, I think that it is possible that the silencer that belonged to the Bambers that was found in the gun cupboard (DRB/1) could have been / was found there on 10th September 1985, and that Robert Boutflour made a statement about its find on that date (10th September 1985) and that his son, David did not contact the police about finding it there (on 10th September 19085, until 11th September 1985, and that his sister (Ann Eaton) handed it over (DRB/1) along with the other items that were found in the gun cupboard on that date, under the identifying marks, DRB/2, DRB/3 and DRB/4...
It is rather odd that if the relatives found the silencer in the gun cupboard on 10th August 1985, that they should not be making any witness statements until a month later, or even reporting it to the police that they had found a silencer in the gun cupboard at whf, until a month afterwards?
It just doesn't ring true...
Two of the silencers (SBJ/1 and DB/1) had been handed over to the police before the find of the Bamber silencer in the gun cupboard, on either 10th or 11th September 1985, the small flake of blood that David Boutflour scraped off the silencer (SBJ/1) could only have been removed after it was handed back to the relatives by the police, and the crucial blood flake that was attributed to Sheila, was found inside the other silencer which belonged to one of the relatives, not in the Bamber silencer...