I spotted a listing for the TNIX user manuals and a set of floppies in Tucker's manual list, so there is a standalone disk and a dump of the file system with the native tools package on bitsavers now, along with the manuals. The standalone formatter seems to be really fussy about what kind of disk it will format. I tried a Seagate ST4096 and a Maxtor 1140, and couldn't get either to go even though they had more heads and cylinders than the Micropolis 1304.