I agree: a nutty little film! Alas, I don't know anything about the Japanese version (even if it's available in Japan on DVD). I didn't even know there was a different Japanese version until you mentioned it.

I always assummed Peggy Neal was a model working in Japan who did some film work (like Linda Miller from King Kong Escapes). Unfortunately, Stuart Galbraith ends her mini-bio in his "Monsters are Attacking Tokyo!" with, "where are you, Peggy Neal?" I know she's also in The X from Outer Space, but that's about it.
"How many cares one loses when one decides not to be something but to be someone"
-Coco Chanel