DP, it's been done mate, have a look at:
http://www.astro-imaging.de/astro/toucam_bw_mod.htm
With a monochrome ccd then the RAW mod makes sense, cause youre just getting 640x480 pixels of monochrome data, you no longer want the onboard colour processing.
Make sure you check out the sensitivity test, it's very revealing!
regards, Bird