Does anyone know these speakers?

Hi eveyone,
I have these speakers for 20+ years and I always wondered what brand is this?
They sound pretty decent and they are made in germany but I can't seem to find any kind of information about them or the company who made them ("Professional").
The specs are pretty good as well (The sensitivity is great!)
Does anyone recognize them?

Here are the links for the pics:
Imgur: The most awesome images on the Internet
Imgur: The most awesome images on the Internet
Imgur: The most awesome images on the Internet
Imgur: The most awesome images on the Internet

Thanks in advance for you help...