I got my hands on a '72 Schwinn Super Sport a little while back, and the bike you've got looks almost identical. While mine lacks the chrome fork that yours has, the components and frame appear to be almost exactly the same. In the early '70s, as the other poster mentioned, Schwinn had a stint with fillet-brazing some of their 4130 frames. Though they used mostly their own components, many of which (one-piece cranksets, stem-mounted shifters,) were not usually seen on higher-end road bikes at the time, what came out were very nice bikes. Most of the measurements on the bike (if I am correct in my conclusion about its model,) are kind of sketchy, so you might have some trouble in finding parts, but I've found the originals on mine pretty durable.

Sheldon Brown's site has a link to an article specifically about bikes like this, which includes a surefire way to verify its origin and authenticity. Check it out, and good luck with your Schwinn, whatever its make. I love them so...