FOUND IT! (the A/UX 2.0.1 update)
...or rather, an incomplete version of it. After much searching, I contacted the maintainer of the AUX Penelope website, and he happens to have a tarball with the disks (4 Mac format disks, plus 11 A/UX disks). He had to change file types as they were munged. The problem is it's missing disk 3, everything else is there :disapprove: :'(