here is the wallset with the stones removed.https://www.dropbox.com/s/6pecqnklq5h315r/Nightfall%20BETA%20wallset.zip
These was a small problem with the secret button small texture.
You are only changing the colors of the dungeon textures for the secret buttons, so you still get the small brick along with the secret button.
So I went in and re-mapped the UV for this model, and aligned it with your wall texture.
maybe the alignement was a bit to good, since now its really hard to spot the small button.
in anycase you can allways change the texture of the button itself with the GMT to make it stick out more.