Has anyone mentioned rust?
Lay on the floor and look up at the underside of the dash board. That's the bottom of the cowl and it tends to rust out around the vent and the heater intake and sometimes back in the corners.
When it does rust out, the water leaks down on the carpet, soaks through and rusts the floors. So lay on the ground and look at both front floor pans. It can also rust the frame rails there and the torque boxes just in front of the floor.
The cars also like to rust above the rear wheel wells, in the front lower corner of the doors and sometimes behind the rear window or around the tail lights.
The speedometer, fuel gauge and e-brake are probably not going to be hard to fix, depending on what someone did to them. Though if the fuel gauge doesn't work you should watch that the other gauges actually do because it's possible that the failure is the voltage regulator that feeds the gauges (easy fix) and not just the gauge.