What system were they from? That might be helpful to list readers (or yield someone with a working system that can read them "natively")
The first cylinder is normal, but after that, the next 21 cylinders don't even have a sector 0.
If the discs were formatted with a WD17xx series controller, it's possible that the first sector is too close to the index hole for the PC's floppy controller to detect.
http://z80cpu.eu/archive/news/comp.os.cpm/threads/49581d115e7ce5d6.html http://simonowen.com/samdisk/faq/