Steyr were a huge armament and bicycle company, making bikes from about 1890 on. The arms company sold off the bicycle arm to Bianchi/Eurobike about 15 years back, and no bikes are produced under that name in Austria anymore. They owned Puch either partly or completely.
The arms company is still in existence.
Velouria of the
Lovely Bicycle! blog has some info about Steyr- she travels to Vienna for work several times a year, and rides a vintage Steyr 'Waffenrad' 28" wheeled roadster when there.
The bikes are of rather good quality, for the most part. Their Austro-Daimler bikes were fast and beautiful road bikes, and the Waffenrad roadsters are second only to the best British and Dutch models. They have more in common with Dutch bikes, but are lighter framed.
That is a very nicely preserved bike. It uses the current Steyr bullseye logo, so might only be 20 or so years old.
I'm guessing the hub is a re-branded Sachs Torpedo, which is quite good. How's the ride quality?