There are two new Judges Guild items for sale at RPG Now.
The first is Booklet K. Unfortunately this is only the initial form of what became the Wilderlands of High Fantasy and doesn't provide much new information.
However Judges Guild Journal (Jun-Jul 1977) is pure gold and provides an interesting snapshot into the hobby circa 1977. It goes along with Booklet K as Mr. Bledsaw talks about how he came up with the demographics rules in Booklet K. Thanks to my Google Fu I am tracking down the sources he mentioned and I will update you when I read them.
The Ghost of Jack Cade on London Bridge
3 hours ago