Well, oh Ducky one, I have an NS Oscar sitting on the bench with a "Pod" style dispersion disc and screen.* My problem is that I cant seem to get an answer on "can I get an Oscar dispersion disc" from anyone in Australia...
So Ill take the chunky hunk-o-brass that is the pod disc and just kiss it off on a lathe.* The dispersion discs are nothing more than a piece of brass (usually) with a bunch of holes to let the water through and (maybe) some kind of ridge on the top/bottom to confine the water.
Id imagine any machinist could fab one up for you if you have the relevant dimensions.* Getting the right sized brass blank would be the big challenge..