Found this as I was looking for help on setting the back focus online. Not sure if it's a double post, but it's worth it! Man, this was simple and helped remove all vignetting.
http://hdfilmtools.com/2008/08/red-rock-micro-m2-cinema-lens-adapter-part-ii/
http://hdfilmtools.com/2008/08/red-rock-micro-m2-cinema-lens-adapter-part-ii/