Hmm... I even tested it with Bandon on the Endar Spire to make sure it worked. I put:
g_bandon001.utc (w/ ga_clothes02 equipped)
in my override and it worked fine.
I noticed that you had N_DarthBand2
in your appearance.2da image. Is that what you named the texture? If so, try it with '02' instead of '2' for the .tga and 'N_DarthBand' should suffice for the .2da entry.
[EDIT: Nevermind, I reread your first post and you had already named the texture N_DarthBand02.tga. Sorry about that, but, if everything else is in order, I'm not sure why it isn't working for you.]