COLP questioned Cook about the exhibit reference (SJ/1) he had assigned to the silencer given to him by Stan Jones, and he told them what I have repeated in this thread, he said he labelled the silencer on that occasion, SJ/1 because he didn't know that Stan Jones had a middle christian name of Brian...
Just for the record, Ron Cook had nothing whatsoever to do with the four exhibits, SBJ/1, SBJ/2, SBJ/3 and SBJ/4, until much later in the investigation, and as far as I know Stans four exhibits, SBJ/1, SBJ/2, SBJ/3, SBJ/4, were never referred to by the exhibit references of SJ/1, SJ/2, SJ/3 and SJ/4...
By all accounts, the original exhibit reference to the silencer found at the scene by David Boutflour was SJ/1, lab item number 22...
with this in mind, it looks almost certain that there was no need to change the original exhibit reference of SJ/1 because there could be no clash involving the need to change it because it was confusing...
Why change SJ/1?