Furthermore, I copied the supplied kernel to my 1.0 system, and tried to
   boot on it. Same thing, and something's funny with my filesystem now too.
   Selecting the old kernel from the boot: prompt won't work, it goes through
   checking for devices, then hangs at the end of that. Booting off install
   floppies won't let me fsck the drive... Any suggestions?

Re-install the old boot block and it should be fine.