Factory stock, yes. But to replace that rear cross still the welds have to be cut. For concourse yeah reweld them. By factory stock I have always meant to make it as close as you can to stock. Of course when you drill spot welds etc you are not factory stock, niether is a big gapping rusty hole either.
As soon as you do any fix it thing it is not factory stock.
I think it is called RESTORATION.
On another note, the long fleet side panels are maybe 80 lbs guessing. I personally had to take the box apart to be able to store the parts inside while they wait their turn.
