You've certainly uncovered some great information for such a rare watch; thank you for sharing! Now that I think about it, I could probably locate some car magazines from the late 1970s without too much trouble. Perhaps some english language magazines specializing in european and sports cars may have the infamous advertisement. I'd be very surprised to find any german language auto mags, but there is always a surplus of old literature at the car shows that I frequent. I'll keep my eyes open!