Guys, thanks so much for your input.
Luckily, by just creating a dummy “AUDIO” folder and dropping it into the main folder, I was able to view the thumbnails in FCP. This was the point where I discovered there was a copy of the P2 file, but with a different name and including the “AUDIO” folder.
So it turned out to be a Merry Christmas for my client after all.
Thanks again, buds.