These floppy images are in Disk Copy 4.2 format.
Tune-Up 2.0 was converted to Disk Copy 4.2 format from the Apple
Legacy Recovery CD.

To write them on *nix:

dd if="image_name.img" of=/dev/fd0 bs=84 skip=1

(obviously replace image_name.img with the name of the image and
/dev/fd0 with the path to your floppy drive)

On Windows I've had luck with WinImage.

To install Tune-Up 2.0, just pop the floppy in and run the installer.

If you have issues with this, you can manually install by copying all
of the *.Z files as well as the installer script to /tmp, opening a
CommandShell, and running `ksh /tmp/installer`.