I ended up getting my hands on a couple of QX-16 harddrives recently and was able to image them using my MFM emulator to dump the drives. One wasn't really that interesting, but the other one appears to have come from a system that was used by Epson of America. On that drive I found what appears to be a fully complete version of the source code for the Epson QX-16 version of MS-DOS 2.11.
Digital Archaeology
I picked up a pair of MFM hard drives that came from two different QX-16s recently, and have finished imaging the drives using David Gesswein’s MFM emulator. Both drives were used with MS-DOS and only had a single partition installed on them.
www.qx10.net