looks to be a 57 cm 1978 Trek 610/613/614 from the serial no. That ID is based on the serial no. but the brochures aren't helping me ID the bike any better.

I have a 1979 57 cm Trek 510 which could be a dead ringer for your bike in terms of the color, the paint issues (pretty good with some bubbling), and the parts components.

You did good at $100.