Thanks everyone. After all of this input and with careful consideration, we have decided....


...to do nothing.

We're going to run the Ford until it completely breaks down and we've set $4,100 a year as a budget to keep it on the road.
The logic is that $4,100 is about the same as car payments, we have no expectation of a resale and we have no need to take on debt. I don't care how the car looks so I'm taking it to a shop and welding the damn rocker panels myself with something to stiffen it all up. I was able to reset the computer and disable some of the automatic features with creative wire snips

So thanks, this was useful.