ditch them, i thought you wanted the inner cover, i have a spare outer like that one.
I looked at using an inner cover from the 450 and just playing sliced bread with it to make it fit to the KX500 clutch cover.
But, the more I looked at it the more I think that making a simple adapter would be the best way top go.
At this point my goal is to make adapter rings that others could take to a local fab shop and say, cut the outside of this cover off to "X" height from the base, weld this on to finish at "X" height, make sure it doesn't leak, bolt the cover of choice on it (As long as it is from a 06 or newer KX450F) and go ride.
I think in the future I may try the sliced bread method but for now I want the easiest solution.