My winter/city/rain bike is an '83 420 set up as a fix gear. It's a keeper, easily the best of the 5 bikes I have had in that role.
One caution: look periodically at the seat stay cap, that oval plate with "TREK" stamped on it. (Middle photo of post
#5 ) Eventually cracks will run across the letters. I saw a crack on my right cap and called the framemaker who has built me a couple of bikes. He told me exactly what the reoair would entail, the time frame and cost. Then said to look at the other side, that it was virtually guaranteed that a crack had started there also. It had. (He would have done the repair on both sides regardless. It takes little extra time and the bike had to be painted anyway.
I felt and still do 5 years later that spending more than the bike probably cost to repair the seatstays was well worth the money. The bike's a keeper.
Ben