Here is the thread discussed earlier and I added the photos also:
http://forums.lugerforum.com/cgi-bin...=000085#000000

And here is the patent drawing from the Luger Book, a good book with nice pictures.
Rick W stated this:
I finally remembered this toggle actioned rifle, page 134 of Parabellum by Bobba. The caption under the picture calls it a sub-machine gun Furrer, designed in the 40's also for use on air-crafts.
Rick W.
Ed