EPSON QX-10 20MB Hard Disk
PT.COM for EPSON QX-10 PeachText 5000 date changed - 02/03/84
and similar references to the QX-10 or EPSON CP/M.
So, this was from a Epson QX-10 CP/M system. Looks to be a soft-water service company from South Bend Indiana. All their books and correspondence from the mid 1980s was on it, along with some interesting disk support software. There's even some bits of Z80 assembler, but they are too disjointed to know what they were for.
I've not been able to get cpmtools to read the disk in a structured way, however, so it's hard to share just the interesting bits. Still working on it.
If you have one of these machines, or are interested in preserving software from it, please let me and we may be able to work something out.