My friend Teun, who supplies many old and new German airgun parts from his business at:
recently had the chance to visit the Diana factory and kindly photographed their
[meagre] collection of old air rifles for this forum. He reports that they seemed to
know little about the vintage Dianas, which matches what I've heard from other visitors
to the factory.
Here are the pics, with thanks to Teun for taking the trouble: