https://github.com/Thalassocracy/Beautiful-Textures-For-Legion This mod compiles old Legion textures made by KillerKiwiJuice. The current Legion textures are a derivative of these textures which have gone through a filter to simplify them and remove certain details. The filter did not work perfectly, and there are certain resulting defects with the Legion models. I (Dissonant) created this mod in order to package the old textures after KillerKiwiJuice dug up the last commit of Legion using these textures and sent me a link.
The original metal textures weren't made by Kiwi, he replaced someone else's textures which were found (if memory serves) to require a commercial license. Unless that license has been purchased then this can't be uploaded as a mod.