By the time I spoke to my son, he'd already got his hands on Spinrite, however, he was four hours into it writing to the disk when I phoned. Something was wrong - it seemed to be trying to save the disc rather than the data. Not sure, trying to get the gist is sometimes hard at a distance.
He stopped the process. There had to be a point he went off at a tangent, but a rerun didn't reveal it.
He then found
Data Recovery Software Products - Runtime Software Products
and could see the files in a few moments. Last news was making a $79 purchase.
We'll see.