Go to Kawasaki's website. You can view exploded parts diagrams of most all there bikes. Find out the part number of your rear wheel or hub assembly, then start checking other years of the same bike and also various years of other model bikes (eg. KX's, KLR's). This will probably be the best way to verify cross compatibility of parts from year to year and model to model.
I know i've used this procedure to verify that the rear hub for my 93 KX 500 is the same as the 250 and 125. Also, since sprocket manufactures frequently list that there spockets fit KX's and KDX'x and KLR's, that would be a good bet that they are probably using the same hub configuration. Good luck with your search!