1981 Fiat X1/9 X19 X-1/9

Up for sale is my mothers Fiat. She bought this car brand new in 1981. Around 2008, she decided that it was time to make the car look and run new again. She spent a great deal of money on this but did not finish the job. She has recently passed, so it is time to sell the car. The car is currently registered as NON OP in California, proof provided.
Here is as much of the good and bad that I know.
Good: Engine has been rebuilt, including new injectors and updated parts that were known to be a problem. The wheels were stripped and dipped to restore back to factory new. New tires (at the time). New master brake, calipers, and pads all around. I believe there is nothing missing from the car, all original, and everything is there. The headlights work as expected, as well as all controls. The car was professionally repainted as well as a subtle pin stripe. The pic reflects stronger than the pin striping actually appears. I believe the interior is original, in good shape, and I believe everything works. The car has never been in an accident, and being out in the desert, is showing no signs of rot, other than a bit of surface rust here and there. The top is removable and as far as I can tell, does not leak in the rain.
Bad: The engine starts up and runs fine. However, it does not seem to have any power. It may be that the exhaust, which has not been worked on, is choking the car. The engine temperature will also start to rise. I believe the radiator has probably never been replaced and is causing the overheating (the car was never allowed to overheat). The brakes, though all new, are mushy. The battery is dead and will not hold a charge.
There are extra parts replaced during the rebuild that are in the trunk.
Any questions, please ask.
Thanks