Where did you visit? Ive been to Linz,Vienna and Tirol. Something worth noting is that around 35% of Vienna is foreign born - the UN headquaters are there for example. In Austira its well over 300,000 are from Yugoslavia alone also. I think you need to visit some rural area to get a good idea of what they're like.
I think curly hair (and wavy-curly) isn't rare among western europeans. I would say it's more (european standards) a west-east decline. Iberia, France, UK, Italy, Western Germany...have a lot of dark curly/wavy-haired people. Austria was the epicenter of an empire wich compelled lots of peoples who were already a mix of various historical peoples (celts, rhaetians, slavs, germans, illyrians, hungarians...) It's not an isolated place, you can find many different phenos there.