you might be surprised to find that this noise is actually the release bearing wearing into the "fork".... i had my 740's clutch done, and was told that my original bearing had "worn a HUGE chunk out of the release fork" the "worst he'd ever seen" so it made me wonder, i assume, pretty much that that could be your problem, but hey. Just be careful tho, because if the arm wears out, then the clutch wears out quicker and doesn't disenguage well enough, wearing out synchros.... Jus ta thought
Az