I've been hacking a bit, and I discovered that if I took the relevant bits from the Debian/Woody CD and put them on a flash, I could boot as expected and start the Woody installation process on the IA1.
Does anyone think that this will be fruitful? I'm not too thrilled with jailbait, really. I suppose that my first hope would be to get a woody-based install that pulls lots of its goods over NFS, and my second choice would be to get a woody-based tiny distro for the IA-1.
I'm still pretty stuck because my usb nic hasn't arrived yet, so my hacking is purely academic at this point.
I don't know the practical limitations of size and debian/woody. Clearly, the jailbait install needed to do lots of funky stuff.