Crawl underneath the rear. The trunk floor extensions will rust where the lower 1/4's do. They can be repaired/fabricated but reproduction pieces aren't made. Going through that with my 66 as we speak. They are cool and fun cars. WELCOME TO FABO!!!
If they're not already rusted out, I would remove the plastic body plugs from the bottom of the trunk drops and then hose them out from the inside with a garden hose. You would be amazed how much dirt and debris will collect down there. It holds moisture and causes them to rust out.
