I wrote a tool to convert the .xbf-files into .obj files. As far as I can tell it is working with almoust all files (I know only one exception: the isradar.xbf).
In some files are more than one mesh. This is due to animation issues. Each mesh has a own name. My tool creates a separet file for each mesh. You can simply join them, but you have to respect the animation information between these files. Most of the time there is an position offest.
There are still some areas where I do not know the containing data is used for.
Here is the tool: http://oresome.rockraidersunited.com/download/262
I am sorry for the undetailed post . Hope it works.