Do you recall what kind of machine and operating system these disks were originally written with? You might have some luck with a local retro computing group. I

Do you recall what kind of machine and operating system these disks were originally written with? You might have some luck with a local retro computing group. I don’t know much about digital preservation and old school storage media, but maybe there was a quirk with how the data was originally written on that specific disk that you just need a retro computer to untangle?