look thru the catalogs at http://www.vintage-trek.com/
with that headbadge it's from 1983 or earlier, can't see if it's screwed or glued, but looks glued. Given the VGT RD and the cheap calipers, it's not a top model, but can't be bad either. I have no idea what he means by "Gyro" hubs, that's a new one.