It is an '83 sport touring model.
That means, basically, it has shorter chain stays and caliper brakes instead of cantilever brakes. Full touring bikes will have more bells & whistles. Check out the '84 620 for comparison. The catalog page and specs can be found here...
http://vintage-trek.com/TrekBrochures.htm That bike also comes with 27" wheels instead of 700c wheels. Tires are easy to get, and pricing can be fairly reasonable. It is an older size rim, however, that hasn't been put on new bikes in about 20 years or so. It does have a nice lugged Reynolds 531 frame. You can research Heliomatic hubs and freewheels, and then draw your own conclusions. For comparison, a new touring bikes like the Windsor Tourist runs $599 from Bikes Direct to your door. If you don't buy the Trek, somebody else will. To some people that's alot of cash, to others it is pocket change. It also depends on the type of riding you are going to do. Maybe a good deal in SF, but I think it is a little high also considering the paint.