Should we discover any more files to recover from the laptop, I may explore this avenue a bit further. If the ZTerm software is present, the trickiest part might be physically connecting the serial port to something else. Not an insurmountable problem.
As a poor Atari owner out in the nowere, I used metal paper-clips bent into shape and welded cables on them to connect my weird non-standard ports to other things. Worked pretty good :-)
SLIP, zmodem, and uuencode are tremendously useful when no other options are available.
I suspect you won't even have uudecode, in which case so long as you can transfer binary files, self-extracting ZIP files should work. Might take a while for larger transfers.
Getting a Real Operating System onto the old laptop would be a benefit. You might want to look into boot-from-floppy options including TomsRootBoot and Trinux. The former fits onto a single 1.5 MB floppy ("superformatted" to about 1.7 or 1.8 MB). The latter uses 2--3 disk images to include a number of more formidable tools.
Trinux still has a Sourceforge page, though I've not dug into it. You may need to hit up Internet Archive for working images:
I don't think that will work on non-x86 architectures. As far as I know, you can't boot linux on 68LC040 at all, perhaps if someone forked uCLinux and made it work with no FPU and no MMU you might get something going, because all the 68k linux variants expect a MMU that works, which on that specific CPU is too buggy. You can't run MkLinux kernels either since those are PPC OldWorld, which came after 68k.
There might be Powerbook Linux boot floppy, though NetBSD might be a better choice. The CPU appears to be a 68LC040: <https://support.apple.com/en-us/112137>
Looking at the reporting, it does seem like the 68LC040 emulation at least worked (just slightly buggy), which is much better than the not-booting Linux of the same era. I should probably not be surprised to see NetBSD run on yet another thing ;-)
I wonder what has been ported to more hardware at this point: NetBSD or bare metal Doom.
Some years back I seem to recall Debian making the claim to support more hardware (if not necessarily the same hardware) as NetBSD. I cannot verify this presently however....
Should we discover any more files to recover from the laptop, I may explore this avenue a bit further. If the ZTerm software is present, the trickiest part might be physically connecting the serial port to something else. Not an insurmountable problem.