When I purchased my 72 the trunk looked to be solid but once I removed the fuel tank it showed its age and neglect. Only about the back 6-8 inches of it are ruined so I was wondering if I could just replace that portion with steel. The car is not being restored to factory glory so I am not concerned what people see under the carpet but I wanted to check to see if there is any downfall to my approach. Any recommendations on gauge to use? Thanks!