Lookin' good with the glow-poxy!
I like the carbon fiber inner idea, but agree that you wouldn't see much of it. But what if a clear plastic tube was bonded in? The aluminum would protect it, so the tube could be pretty thin, and could be epoxied in at both ends to seal the light. The loaded batteries would be visible through the plastic, which could be good with Surefire or other colorful batteries (maybe AW's IMRs?).