One of the really stupd things that I did was buying a cheap fiberglass trunk on FleaBay. I saved $25 but ended up spending weeks and months of work on making it fit.
The inner trunk frame was twisted. This means there was no weather seal on some parts of the trunk, when the weather strip is installed. And on other parts there was no room for the weather strip at all!
I realized after doing this, it might change the shape of the trunk. Thus I would have to revist all the body work already done.
To heck with it. There are a lot of problems with shelbys leaking ehaust gas back into the cars due to lack of a trunk seal. This is really a safety issue, so it has to be right.
I ended up cutting wedge shaped slices of the trunk's inner fram and 'glassing it back together.
The black lines show the cuts