So what I've heard and experienced on system 1s is this:
The power supply probably needs rebuilding
The mpu might be good unless there is battery damage
Driver board is repairable
The interconnect and several connectors will need to be repinned
The small transformer needs a fuse.
The displays are usually good but might need to be burned in (easy) if they are dim

This is a desirable title and if it was in northern CA I'd buy it. But sys 1s take a specific startup sequence to test correctly before you can turn it on safely

So red flags:
Small transformer is melted or burned = run
Battery damage on mpu
Look for burned coils and manually push in the plungers on each one. Every burned coil is likely a driver board repair too