I like Thief set very much and actually prefer it to any other clothing. But there is a minor flaw in it - namely hideous leather triangles (especially the back one) hanging from the mask. So I happily got rid of them - and then decided to share. I give you two variants of this little flavour mod: with front triangles and without them.
Installation is as simple as with any graphics mod: just put one of the included files into your dsfix\tex_override folder and set enableTextureOverride 1 in dsfix.ini - but I'm sure you know this already. And, of course, this mod would be incompatible with any other modification of this file - that's obvious.
To my knowledge, both versions do nothing except removal of triangles - but please do notify me if you notice anything weird.