Thanks for sharing that Rick. My part is dimensionally based entirely on the WNW part, and indeed they appear to have gotten it right. It makes senses that the D.III radiator would be interchangeable, after all the D.V/a wings essentially were as well...
My question remains whether the D.II (wing-mounted) radiator was also interchangeable. I suspect they might be, but I confess I haven't done the research.