Thank you Fernando,
I am very unsure, my first thought was Crete but the handle would be more as unusual for a Cretan knife. I've posted it here because the seller seems to be sure that it is German or Middle Europe.

For marks in the blade and for a punched hallmark I can look when I have it in my hands. To this time I will post also better pictures from the inlay.
Do you think the thread should be moved to the ethno forum?
Regards,
Detlef