Actually I did make a patch... up to the metal detection shader;  you can apply it, and then copy the more recent shader on top. It's called "ao_and_terrains.patch", and you have to apply it in the /binaries/data/mods/public/ folder, because that's where I did the svn diff.  Go to the folder and type patch -p0 -i ao_and_terrains.patch After that, to get the metal detection/depiction shader, just copy model_common.fs to the folder /binaries/data/mods/public/shaders/glsl/  overwriting