Bit hard to see but the tunnel and the cone going to the firewall is 2 pieces They were both cut to shape and then used a press to shape it up. Bend the mounting edges first and the cut them at intervals so you can roll the shape, and again more welding. That was time consuming and lots of cardboard used to shape it first. Try a bit of origami to get you in the groove.lol. The 3rd pic you can see where it’s welded to the firewall. Full disclosure, my mate was the super clever one, we chipped away at it over many jack and cokes for nearly 10 years. More money than anything but it also evolved over that time which was good.