You need to step back into 1984 and then look at your Mac 128k from a different lens and then think about what you have. The Mac 128k is a door stop today and is totally underwhelming... by today's standards. It's rich history is why you buy them. Being able to try out the software that was available back then, as limited as it was, is another reason to own one. Be grateful that you can.
I have some systems from the 70's that if I get a monitor/command prompt, I'm very happy. If I get a floppy drive to work and can get it to boot a floppy, over joyed... literally. Case in point is my Processor Technology Sol-20 with Helios II drive. You can count the number of working units that exist today on one or two hands. I only know of three or four. As another example, I'm just happy my IMSAI 8048 occupies the same space that I do. I have not yet even powered it up.
Sometimes you have to be thankful you have the real hardware to play with. It is desirable by some and they'd be very grateful to own one or even have the opportunity to play with it in person. Maybe that's going a little too far with a Mac 128k but there are systems out there that people appreciate just knowing they exist. I hate to be preachy but enjoy your Mac 128k for what it was, not what it is.
Edit: After a quick look, I did find this site with some disk images: http://tkc8800.com/page/Macintosh-128k-512k-disk-images These should work on a Mac 128k if yo can make the disks.