Well its still a bit rough round the edges but it works! Knocked up from a scrap 12mm bolt. Far better than that plastic nonsense and has a lovely click when closed.
Just need to get the bluing process sorted and then its time to strip the paint back.
The standard one also clicks as the barrel catch should be locking up on the steel ring, not plastic. Yours will be much more robust, I would blue it with G96 Crème, 2 minute job.