My observations ~ notable how scarce for sale, 1948, 1956 & 1957 threepencies are. Thanks for your hard work on this one, Declan. A very useful and revealing exercise. I'm not quite sure precisely what it tells us quantitatively, but I think it does show up otherwise hidden scarcities. I know when I was completing my threepenny bit collection 2 to 3 years ago, it took me a long time to drop on a decent grade 1948, which surprised me. They perhaps fall into a category of "forgotten" coins. Before the big withdrawal and meltdown, they were not really thought of as scarce ~ although mintage was not excessively high, and in 1948, positively low. Consequently, they were not hoarded. Maybe not even collected to any great extent. Hence they are now surprisingly scarce in the higher grades especially.