Thank you! Well, I like how the controls and physics of Kobo II came out, and would like to build a proper game around that at some point. Deluxe was technically finished as soon as it was a working SDL port of XKobo, but it became a messy testbed for random ideas, and definitely needs some cleanup, and probably some sound and graphics updates.
Anyway, these three projects are physically related; Kobo Redux is (so far) based on the Deluxe code, the scripting language/engine of Kobo II is used in the Redux project, and Redux uses the same sound engine as Kobo II. Part of the plan here is to share more code between the projects, to somewhat remedy the mistake of using custom code for basically everything.
As for Deluxe, I've started a new repository for it (https://github.com/olofson/kobodeluxe), where I've pulled in fixes from Debian for starters, and I'm going to backport various bits from Redux, including the SDL2 rendering, since SDL 1.2 is obsolete. Not quite sure what to do after that, but at least, I think the "unbeatable base" issue should be fixed, and there should be a more strict campaign mode, but I don't know... Of course, Kobo Deluxe is, and will remain, an entirely Free/Open Source game, so I guess people could join in, but C++ scares many potential contributors away, and even more so if the code is ancient and messy, so my expectations there are low. :-)