On the Ebay car, you can see the front tower gusset was welded with a solid bead all the way around it. That's not the way AC did it in the 60's, they just put a few 2" or so long stitch welds on the tower. You can see an example of this in the photos of the car Canepa is restoring:
http://www.canepa.com/racing/Cobra2/index.html