Tatto v.1.8
The posting, by Lou "Firestriker" Volland, is self explanatory, and could prove an intersting approach to painting.
The way I see it, one would capture the MAPPED x file in mdlcommander, and using Tatoo, be able to "paint" directly on the resulting mesh.
I guess that once the colors and texture are made, then you can go back in with dxtbmp or some such and deal with the alpha channels and such.