Get Stuffit Lite here.

You can just burn the .sit files to a CD, read the CD in one of the Macs, and make the floppies using one of the Macs, right?

Do you have access to a Mac of any kind, including a newer one?

In all honesty, given the tedium associated with making copious amounts of floppies for 7.5.3, I think the easiest way to install would be to find an installation CD on eBay.

Congrats on your successful liberation!