My Xenix box is actually a little older. It's a Nabu 1600. It has an 8086 CPU plus an MMU built out of TTL chips. It uses ST506 disk drives (broken now).
The filesystem is the standard 7th edition Unix filesystem. Partitioning is compiled into the kernel (if I remember correctly). Actually, so is disk drive geometry. This makes it hard to substitute other drives.
The original Nabu Xenix port was done by HCR, starting from Altos work done by Microsoft (and possibly SCO). Years later SCO bought HCR, but that is another story.
Xenix at this point was really 7th Edition Unix. Right down to using the Ritchie C compiler, not PCC. The system was very much like a PDP-11, right down to the limitation of 64k bytes for code and 64k bytes for data ("split I and D").
Obvious ways of getting data off this machine (might apply to the OP's machine): uucp (9600 baud is probably the limit on mine) or tar to raw floppies. Using 7th edition filesystem floppies is probably a mistake. Linux could surely read tar files off of raw (no-filesystem) floppies.