Well, let's start from the beginning.
I have just made a script from scratch for the DFS/000 archives:http://aluigi.org/bms/area51.bms
Next step is having a list of ALL the file extensions and trying to understand their content.
For example the textual files require no knowledge (it's text), XBMP are probably headerless bitmaps (so I guess relatively easy to convert), audiopkg are painful, ANIM and FXO probably unknown formats and so on.
It's a big work so I think you should find someone really interested in the project or there is the risk of spending months with new bits of information retrieved by people here and there.
Anyway that's the starting point.
Cool, thank you. I've been waiting over a year hoping to find more people interested, so I'm in no hurry. I've been meaning to get around to making a list of files, known and unknown - so that is one of my next steps. And, yes, XBMP files can be converted to TGA using one of the two programs I linked above "XBMP2TGA", created by a user that goes by the name jTommy. I'd like to contact him but both of his websites are gone and archive.org yields no direct contact information that isn't deactivated (it also doesn't help that the sites are Russian). I emailed http://www.ctpax-x.org/index.php?lang=en
asking if they could help me get in contact with him; no response yet.
The research continues.