Do you want to try an experiment?
I have uploaded a directory of textures here: http://www.sendspace.com/file/1l5kkd
where all the textures in my Data Files/Textures have been replaced by white textures that have the name of the texture written on them.
It allows me to easily identify what textures are being used.
I use these textures by first moving my real textures to a save place: "Data Files/Textures" --> "Data Files/Textures.orig"
Then I put these named textures in their place, and start Morrowind. Everything looks horrible, but you can see the names of the textures written on the textures themselves.
Anyway, it works for me, so it might work for you.
Also, that archive is full of named textures for all sorts of mods I have experimented with, so it probably has all kinds of textures you would not have, and it may be missing textures that you have that I do not. You might have to install these named textures on top of a copy of your current textures.
The most important thing is that if you do try this stuff, please make double sure you have a proper backup of your current textures and know how to restore them after the experiment is over