Flush or transplant?

I don't think I would try the screen; it is not like a fuel filter in that if it clogs, and the engine stops. It the 'coolant filter' clogs, you can fry something pretty quick. Never seen that much gunk inside an engine cooling system; congrats!

How are you telling that the radiator is clean: From the lack of crud coming out with a flush? Try it again and tap the radiator tanks medium hard over and over with a screwdrivers handle and see if stuff stops loosening and coming out. Reverse the flow and turn it upside down and do it too; you may be surprised what will become dislodged; I never consider it clean 'til it passes this test.