> My first attempt at restoring 1991 Learning Company Spellbound for DOS for my children is dubious. Despite being stored nowhere near magnetic sources, there are read errors on the 3.5 inch floppies and Linux could not mount them.

FWIW, it's long been my experience that floppies (like CDs and DVDs) have a half-life and they degrade quickly upon reaching it. You'd have been lucky to be able to recover those in 2001. Now? If at all, only high-end forensic tools could recover them.