Reinforcement pans
This is what was left of one of the  reinforcement pans. It still was able to tell me a lot when compared to the new reproduction pans.
Above you will see the reinforcement pans that I purchased from Lancaster mustang. The price was excellent but if this was a concours restoration they would be totally unexceptable. The access holes were off by up to 1/2" from their proper location and the biggest flaw is they angle slighty when installed to the floor because the floor has a slight outward angle from the tunnel. The factory pans have a slight angle built into the longer wall to compensate for this and make them lay flat across the bottom from side to side. Below is another replacement pan from another parts supplier that has the angle in the side.