In 1945, as the Manhattan Project was nearing its big climax, a way was needed to transport plutonium cores for the implosion-style bombs. The carrying case that was made is an obscure corner of nuclear history, and a replica was on my to-do list for a long time. Halloween 2019 provided an excuse to finally make it happen.
While the materials don't match the original, everything else was made as accurately as possible. The reconstruction drew heavily on photography from the Los Alamos National Laboratory Flickr archive, and the account in Twilight Time by Ralph Sparks, the guy who did most of the machining on the original.
I'd still like to make an even more accurate replica someday, using magnessium for the box with a tungesten core of the correct mass at the center, but this will do for now.