I bought a Trek 520 touring bike yesterday and although the components date from oct/nov 88' the frame has differences that are not on the 89' frames depicted of vintagetrek.com.
I know the bike is original as it is in factory new condition right down to the tires. I don't think it has more than 50 miles. But it was very dusty from sitting.
Some of the differences are the rear brake cable mounting and pinch bolt. This bike has a bridge for the cable and the the 89's in the brochures don't have that until 91'?
The rear brake cable also seems far to long up front. I will post some pics of this time capsule 520 tomorrow.