that will be the worse investment you will ever make! The entire body is out of wack, and certian areas are just way way off. for the amount of money that you will be putting in to it your better off machining a new one with correct dimensions. Trying to machine new parts for it, it will not match up with the body styling. Once you do make new parts for it, say you make a front bumper and bond it to the body, the hood and fenders will be off and you decide to make new ones to correct it. Than the roof line is off or is too small or to wide, so you make a new roof and so on and so on until you reach the rear bumper. By the end of it all you pretty much have made a new plug and dump 6-8k extra in to it and have two different bodies. One that you started out with that you end up trashing, the second is pretty much a newly machine plug.
It's not a mold nor a plug. Its a fiberglass part that was made very poorly and that is the reason he wants to sell it.
For the amount of money that you will be putting in to it, I can offer you a fully machined plug for the same price as the listing and the dimensions will be correct to the real car. I'm just saying, you have options, don't just jump on something because you see the price is cheap, there is more money and work involved than you know.