Amazing stuff!
Seeing what you've done so far, I wonder how much more moddable the game is - will you guys finish off by turning this into a completely different product one day?
Well first of all we're all bound by the Empire source license, so simply reselling this is out of the question, and we can't redistribute the original datafiles (models, textures, etc) so making a true "free" release would be a major undertaking.
Then there's the fact that the code is old and ugly in every aspect. It's plain C with source files that are thousands of lines long. Thanks to it having directX bolted to everything cross platform support is never going to happen (there was an openGL branch but it's dead Jim, AFAIK), upgrades to later versions of DirectX are a big undertaking too.
I'd say what EECH really needs at this point is a rewrite using open standards/APIs and a high-level language (C++ or even Java).