I am riding a 1985 Trek 420, which was originally marketed as a sporty touring bike. When I purchased the bike, most of the components were original, however most components had significant wear from 35 years of riding and needed to be replaced.
The biggest upgrades were building a new set of wheels and custom decals. The decals are patterned oxidized silver leaf. If you would like to know how to make this style of decal I have a tutorial here.
Trek 420
A unique aspect of this era of Trek bikes is the investment cast lugs. In particular, the headtube/lug is a single piece. Where a standard headtube has a continuous internal diameter, this design has a shelf in the middle that makes it challenging to remove the headset cups. I am unaware of any other makers who use this design and it was only in production for a few years in the mid 80’s.
Another interesting aspect of this bike is a partially internally routed rear derailleur cable. It runs through the right chain stay, however there is no routing tube so it can be difficult to replace.