Recovering original .MP4 with metadata from "Original Media" folder

I've been under the impression that the files stored in the "original media" folder are exactly that - 1:1 originals.
Seems like I was wrong...
I have a project that includes several clips shot on a GoPro Hero 7, that were imported as "original" media. Now that I need to work with the originals, I realized that FCPX created .mov files out of the .MP4 files, and (probably) also deleted the original metadata that was included in the MP4s. When I run the mov files through mediainfo there's way less metadata to find than in a raw file from the Hero7.

Is there any way to re-wrap the .movs to .MP4 and get the original metadata back? I have a hard time believing that FCPX would just delete all that data during import, it has to be stored somewhere..?

Thanks!