Shemeska
Adventurer
As for the missing demiplanes: I'm always on the hunt for more information. However, while I cannot recall the Isle of Black Trees (I'll check it out!), I do seem to remember the Clockwork Gap showing up in a Dragon Magazine well into 3e, while the diagram is limited only to AD&D 2e stuff.
Though maybe there's an older version that I'm missing! Do you know if it showed up during 2e in any capacity?
The Isle of Black Trees showed up in 2e's 'The Eternal Boundary', though little more than a name drop. It got a tiny bit of detail in 3e (in the same article that featured the Clockwork Gap).