Mike,
Are you sure those notes are from DS Jones' interview with COLP? I will of course defer to your greater knowledge of the documentation, but I always thought they were from his interview by the Dickinson Inquiry in 1986.
The reason I mention this is that, as you will know but others here may not, Stan Jones did give a statement to COLP in 1991. That was a statement dated 29th. August 1991.
Note also that there is missing from your attachments a follow-on page in the [1986?] notes of interview that is very significant and puts the matter in its proper context, because it records the meeting later that same evening at 9 p.m at the White House when DS Jones hands over the keys to the relatives.
DS Jones' statement to COLP in 1991 directly contradicts what he told the Dickinson Inquiry in 1986.
What he told the Dickinson Inquiry in 1986:Myself and DCI Jones met with Jeremy on the 9th. August 1985 at 7.30 p.m. Mugford, Eaton (Ann) and Christopher Nevill also present. Discussion with Jeremy included mention of the silencer. I think I had discussed the silencer previously [not specific about with whom]. Drawn no significance from it. At 9 p.m., I handed over the keys to the relatives.
What he told COLP (the Bamber Inquiry) in 1991:No silencer found on the morning of the 7th. that I know of. It wasn't discussed or even thought of as everybody assumed it was murder-suicide.
Note that there is no mention in the 1991 statement of whether the silencer was discussed in meetings with Anthony Pargeter and Ann Eaton on the 8th. or with Jeremy on the 9th., though he mentions both these meetings in his 1991 statement. I believe that we can take it as implied by DS Jones that the silencer wasn't discussed, since otherwise he would have mentioned it in his 1991 statement as that is what he was being questioned about. This of course contradicts what he said in 1986.
My view:(i). I have no doubt that DS Jones' 1986 version of events is more likely to be the correct version. When questioned by the Dickinson Inquiry, DS Jones' memory was fresher and he is referring specifically to 'the silencer' (definite article), which can only mean the certificated Parker-Hale silencer. However, it is not clear whether DS Jones means to imply that a silencer had already been found, or only that a silencer was noticed to be missing. Either of those things would be of immense significance, but it is not clear which he and DCI Jones meant.
(ii). The 1986 document refers to discussions about the silencer prior to the 9th. involving DS Jones, but it is not clear whether this was with Jeremy or DCI Jones or someone else.
(iii). The 1991 statement directly contradicts the 1986 interview. There can be only one explanation for this. In 1991, DS Jones was being interviewed specifically about the silencer. He has clearly for some reason decided to change his account and omit reference to any discussions or suspicions about it.
Anthony Pargheter brought up the silencer on the first day. The police then asked Jeremy about it in his witness statement. Ann Eaton overheard this and was then able to later contradict JBs statement by making it seem the silencer was on the gun.
DS Jones was present at a meeting on 8th. August between DCI Jones, Ann Eaton, David Boutflour and Anthony Pargeter. I'm therefore wondering if Stan Jones' reference in his 1986 interview to "previous discussions" about the silencer is to that meeting the day before.
However, while I consider Stan Jones' 1991 statement to be unreliable (for the reasons given above), at the same time I note that in that statement he mentions both meetings on the 8th. and 9th. and I cannot think of a reason why he would not mention that the silencer was discussed on the 8th.