Success: Inspired by sevenn, I got Midori to boot off of the external CF (hdc).
All Midori features seem to be working including NFS and Samba mounts as well as X, Opera etc. Most important for me, it works with my 3C460B USB ethernet. I did check that it has no dependencies on the image on hda.
1) Get and install wildwilwes' midori IA1 V3 build kit from http://www.ia1hacking.com
2) Use xxd or your favorite hex editor to edit the binary file target/cramfsboot.bin
- Change byte 510 (0x1fd) from 0x03 to 0x16
This is a quick-and-dirty way to avoid getting the full Midori build kit and rebuilding cramfsboot.bin
3) Change all the "hda" references to "hdc" in the following scripts:
4) Rebuild the midori image (run the build script)
5) Write the new image to the cf card (dd or dolly etc)
6) Change your IA1 bios to boot from the D: drive
continue from step 7) of sevenn's post.