Hi Alfred,
ok, never seen. Was this horn ever used in our cars?
...Wolfgang
Hi Wolfgang, no, never on a W113 car. I believe these horns were made around 1990-2000 and few came with the 290Hz/345Hz combination, most were 325Hz/400Hz.
I found this (290Hz/345Hz) horn pair at a swap meet and thought I could just exchange the connector for the ring-type connector. Well, as you can see that does not work.
They show up occasionally on eBay.