I thought about doing that to my Excalibre, but I didn't have access to a lathe at that time, and have now sold the gun. But I know where you're coming from, because the extra length of a moderator slightly spoils the nice lines of the gun. Problem is that there's not much room and the diameter of the shroud woold not be very large. My gun was not terribly loud though, so it might work ok.

Would you be shortening the barrel?