Lets get the facts right, the silencer seized at the scene by Stan Jones on 7th August 1985, was not exhibit SJ/1, it was not exhibit DB/1, and it was not exhibit DRB/1 - it was exhibit SBJ/1...
The silencer Stan Jones received from Peter Eaton on evening of 12th August 1985, did not have an exhibit label of any sort, not SBJ/1, not SJ/1, not DB/1, and not DRB/1 - it didn't have an exhibit reference at all by that stage...
The silencer shown to PI Bob Miller on the morning of 13th August 1985, did not have an exhibit reference by this stage...
The silencer handed to Ron Cook to enable him to take it along to the lab for examination by Glynis Howard on 13th August 1985, did not have any exhibit reference attached or associated with it...
This silencer had no exhibit reference at all, until Ron Cook attached a brown CJA exhibit label to the aforementioned silencer, marking it by the reference SJ/1...