For the life of me, I can't find anything on that pistol, but I do remember watching an episode on the Military Channel years ago about the development and testing of pistols during that time period. There was a German design, but I can't recall if it was the Knoble. It was in .45, but for some strange reason, I think it was a Luger. Something like 4 were ever made, and they reside at Colts museum if I recall correctly. I'll keep digging as you've peaked my interest in the topic.
**UPDATE** Apparently this is the one I was thinking of, is it the same as you saw? http://www.lugerforum.com/45Luger.html