Using the Vintage Trek website, I believe I’ve narrowed down the year to 1981, but am unsure if the model. There are no tubing stickers and some of the parts have been replaced. I think it’s one of a 413, 613, or 614 due to the Suntour GT dropouts. I believe the wheelsets were swapped at some point as well as the rear cassette (it’s a 5 speed Suntour Pro Compe).
by gladhandbart