I just discovered this thread. Just wanted to throw in, that I also wrote a little tool to dump the Monkey1.pak file and write out DDS textures.
Serge already started a proper GUI which would ultimately allow easier modding I suppose.
Anyway, here is my (hackish) source in plain C:
Sample image (copyright LucasArts):
@Serge, two questions though:
Do you plan to release the source code of your tool?
And do you know what the table at 0x28 (referred at 0x8) is for?
I also haven't looked at the binary xml yet...