Looks very similar to this 1980 LeTour:
http://www.trfindley.com/flschwinn_1...0/1980_06.html Based on the dropouts, crankset, centerpull brakes, chrome tipped fork, and 1020 frame it is definitely from that era (mid 70s through 1981 or so.)
I just did a quick search though, feel free to page through all the catalogs at your convenience:
http://www.trfindley.com/pg_schwinn_cats.htm