Finished this '91 Trek 400. I bought it for its Mavic/Superbe wheelset that I needed for a Schwinn. I found a Trek wheelset in super shape that came off a similar, but older model. Most of the components were already on it, including the triple crankset, ARX rear mech (without a barrel adjuster), and Accushift shifters. With a Suntour 6-speed freewheel I added, it's indexing rather well. I doubt that will last for any long term, though. It just uses brake housing for the RD. But the right shifter can switch to friction pretty easily. If my niece can stand over it, it's all hers.
Total spent on this once-$50-bike is now $200, but includes new consumables, a new cartridge bb, and some nicer parts from my bin, like the seatpost and saddle. But I did get an awesome wheelset out of the deal.