Ok. One more post just to clarify something.
On the left is my original project, exported with 'anamorphic 16:9' UNCHECKED and then reimported into my new project.
On the right is the new project, with 'anamorphic 16:9' CHECKED.
Excuse me if I'm being duller than an in-flight magazine produced by Air Belgium, but is the resulting video from my original project already correct without me having checked 'anamorphic 16:9'?
What are the consequences of me just using this file rather than going through the entire editing process again?
The grey bars sandwiching it would suggest that Final Cut has recognised it as an anamorphic 16:9 file, even though this option was unchecked on export.
This is so freaking confusing!