The unfortunate part is the Floppy on the Duo was also a dud. Its takes the disk in, but it does not read at all, and then asks to initialize.

Click to expand...

The drive mechanism would most likely just be that of the standard powerbook floppy from that era. It may just need to be cleaned and lubricated. I have two fully functional Duos and a DuoDock, but have never seen the external floppy or minidock. Can the drive be disassembled for cleaning/ lubrication? If it can be, there are instructions around concerning how to go about rehabilitating ye olde floppy drives.