Well, I'm pleased to announce that Marcio himself did get in touch (he's got a lot of fun Palm and retro projects still underway, incidentally) and graciously consented to relicense Plua2c, the "cross-compiler" portion, under the same MIT license as Lua itself. You can now download the source code from Github, which I'll keep maintained.
As for Plua-the-Palm-app and its various components, I will still be hosting the .prcs on Plua Revisited indefinitely, and Marcio and I have been discussing how we can add some improvements such as expanded screen size support and the like. This means Plua has a future again, and I couldn't be happier. Thanks, Marcio!