Build a Classic Mac clone, a plan for everything but the disk drives:
The classic Mac hardware clone seems almost doable, except for the floppy drive. Without a working floppy drive (or equivalent), the Mac clone would do nothing but boot up to the screen showing a disk with a question mark (remember that one?), or the “sad Mac” screen. If there’s no floppy, then there’s no Mac clone, end of story. But there’s also no simple way I can see to build and test a Mac clone floppy subsystem in isolation, without all the rest of the pieces present first. It appears that the only realistic path is to build everything at once, and hope the floppy problem can be solved, otherwise the rest of it will be useless. That’s not very appealing.