“There is already the dual front disc brake shown !!! Maybe that is a speciality for austrian market ?!?
Is it a Z750LTD S1 and a half ???”
yes, dual front discs are original. I did some further “internet research” and apparently Kawasaki produced two versions of S1 model. If you look at the document I got from Kawasaki, the S1 model pictured there is “American sports model”. It has single front disc, shorter rear fender, indicators are on the handlebars at the front and under seat in the rear. Maybe there are some other differences as well, I’m not sure.
I found one S1 American model on the internet (at least I think it is), it looks like the one in the description. Here is a photo: