The stem-shifters are one reason I sense a late 1970's date. Could be early 1980's as well. I can see it's an actual Austrian model. It wouldn't make sense to import the later Japanese models into Europe. The Japanese Puch's were largely for the US and Canadian markets. They sold through Sears under various names.

Last Analysis: That is a very nice bicycle! Puch's have developed a mystique in the USA. Many people are looking for one. And with good reason. Hang onto your find - is my advice. Worthy of restoration and/or upgrading.