I took a look into it. It might work but this is not really the preferred way you want to add a mod. Directly into the core files overwriting stuff. It will break with every update. And overwrites any updates Radiant makes into these files.
You might want to take a look into this
Or this: http://stonehearth.net/2014/01/14/desktop-tuesday-a-peek-inside-the-modding-api/