What is interesting, regarding the detail recorded in the above diagram, is that DS Davidson took these two cast impressions (ND,48 and ND/49) on 1st October 1985, and that he identified regular scratches in these - consistent with the pattern of the rifles metal end cap that normally screws onto the end of the threaded barrel. With this in mind, I would like you all to consider what DS Davidson said to the COLP investigators in 1991 / 92 - when he was being questioned by COLP about the existence of a paint sample bearing the identifying mark RC/1 which came into existence on 8th August 1985, Davidson told colp THAT THE REASON that paint sample (RC/1) was taken on 8th August 1985, was because some paint had been found on the end of a guns barrel, downstairs. He reiterated to COLP that he was not talking about paint being found on the end of a silencer, he was specific, he told them he was referring to paint found on the end of a guns barrell...
It becomes clear to me, that the marks of which DS Davidson made casts, had been made by the end of a guns barrel, not by a silencer, and more importantly, the gun barrel which made those marks, could have been made anytime before the day of the shootings...
I have no doubt at all in my mind, that additional marks were made on the aga surround by use of a silencer, or two, or three, which would explain why ingrained paint was found in the knurl of one or other of the silencers...