If you remember, someone before me cut off the part of the coupe's lower body that bent outward between the wheels, (about the bottom 6"-8") on one side, but the other side was still present. The side that was still present was paper thin with many pin holes, so I cut it off as well. With the crusty sheet metal gone, I can now see the crusty and mostly gone lower body structure. Just for your info, originally these cars were built with several formed sheet metal boxes. Basically, the outer rockers and floor board formed the body structure the rest of the body was built on top of. The outer rocker runs from the firewall to the rear wheel well and is formed with the floor pan attached to it. The inner rocker is spot welded to the bottom outer edge of the outer rocker and bends back towards the center of the car about 6" before it bends up and is spot welded back to the floor pan. The firewall brace is spot welded on top of the rocker assembly and consists of several pieces of steel all spot welded together. The outer firewall brace part rises up to the cowl and bends 90 degrees around the front to meet the front portion of inner firewall brace structure. The rear edge of the firewall brace is spot welded to the outer part of the "A" pillar (front door post.)There is another part of the firewall bracing inside the car that welds to the firewall itself, the upper cowl, the door post and the lower windshield header. From the top of the cowl down to the floor, the door post ("A" pillar) has a formed flanged channel (open side facing inward) with cut outs for the door hinge assemblies to bolt to. There is also an inner door post that welds to the flanges on the channel and back to the firewall brace. The door post above the cowl consists of several pieces of formed sheet steel that form the one piece inner windshield header that surrounds the entire windshield and is the inside portion of the pinch weld the windshield gasket sits on. The stamped cowl and the stamped roof skin form the outer windshield header and the glass pinch weld. The firewall is a stamped panel with 2 side and a top flange that spot welds to the front bend of the firewall braces and the lower edge of the cowl. There are 2 forward body mounts under the firewall braces on each side of the body shell.

As we move rearward on the rocker assembly we find the rear door post is also a formed channel that is welded on top of the rocker assembly. The open end of this channel is towards the rear. The outer body panel is spot welded to the outer edge of the channel and extends down to the outside of the rocker assembly, and up to the roof seem under the rain gutter. The outer panel also forms the outer edge of the quarter window pinch weld. There is bracing that welds to the inside edge of the door post that is the part the trim panel screws to. It also welds to the floor pan, the rear wheel well, and the stamped inner quarter window support and inner pinch weld. The rear wheel well closes off the end of the rocker assembly, welds to the outer body panel and the floor pan. Under the floor are support pieces that are formed channels that spot weld to the inner rocker and the floor pan and run across the car. There are at least 4 of these braces and they are also used as structure points for body to frame mounts.
For your entertainment, I have pictures of most of this structure.
This picture is the bottom of the "A" pillar/door post/inner firewall looking from the inside. you can see where the car was cut before it came to me.