I am a bit surprised how some enthusiasts immediately discount an unknown gun, with apparently 100% certainty, that it is homemade and not a serious prototype, based purely on its appearance and first impressions. So I would like to put this skill to the test, and challenge Ed to tell me which of the following (if any) are true prototypes and which (if any) are homemade jobs. And like with any good exam paper, can you give your reasoning?