Your own grasp of reality seems fucking tenuous at best.
Kids today wouldn't know proper knife culture if it stabbed them in the eye. There's nothing like a home-made effort knocked up from razor blades, lollipop sticks, matches and duct tape. This could be disassembled and disposed of after use in a matter of seconds, and its mostly harmless sub-components were unlikely to retain fingerprints. "What were the matches for?", you ask? These were spacers for a twin-bladed construction, used to deliver the infamous Glasgow "double stripe". The theory was that this made it much harder to stitch someone's face back together again afterwards.
Jimmy Boyle was most definitely a cunt.