@spinflip Try using recovery software like Recuva or WinHex. Best of luck. PS Always make backups. Boring but essential!
@spinflip I hope you're making progress with recovering your files. It can be a slow and fraught process. Maybe you could air your concern(s) on a Raspberry Pi Forum (I'm sure there must be one). If you have doubts about the disk's surface integrity, I would thoroughly recommend Gibson's SpinRite V6.00 Release 1. It's proved a life saver on several occasions. If you need more info or help about this, just let me know.
@spinflip Glad to hear the good news but always make backups. Always! Best Ian
@iankenway thank you, and I do semi-regularly! This one's a bit difficult, as it's a media box with a few TB of video that could all be replaced without *too* much effort if needed
@iankenway turns out it was just a file system integrity issue, and fsck brought back everything with minimal effort.