Tom and Alfred,
Alfred, I don’t have the bakelite connection plate in the switch, the contacts are attached to the housing itself. At the moment, I believe that may be the difference between the 280 and the 230. The PO has definitely messed with the wiring.
Tom, based on your explanation and Alfred pictures, I created a pic of how I understand the connections should be made? As far as you remember, does your housing look like mine or like Alfreds? I am also restoring the lower switch part. My turn signal wasn’t staying either. I found that the rivets of the little arms were broken, allowing them to tilt. I just drilled them out and cut M3 thread. (As described in the restauration guide). I am waiting for suitable screws to re-assemble. I am attaching some pictures.
Thank you very much to both of you.