Hi Guys, I recently bought this GDR Ruhla from an antiques dealer for 12 EUR. I loved the looks of it (especially the plastic case) and the history of the brand. I have some general understanding about the GDR period of watchmaking in Germany and the importance of the Rukhla brand back then. Nevertheless, I can't seem to find specific info on my watch. I'd like to know more about: 1. The year of production: the design looks 70s to me... 2. The movement 3. Actually what makes me most curious: what was the reason the case was made from plastic? Was it to avoid magnetism? Or maybe it was cost effective?