Finally managed to create a bootable CF from scratch and wanted to post a warning about the 3 USB readers I had to go through to get there. I tried the following first with no success:
ImageMate Dual Reader SDDR-75
Lexar Media purple CompactFlash Reader (also branded as Ritz Camera, Kodak)
In each case, I could see the CF in fdisk and in ranish under Win98 SE, but no matter how I formatted or sys'd the flash, I'd get "Invalid system disk" or "Disk I/O Error" when trying to boot on the IA-1. Got myself a Dazzle (Microtech) ZiO USB reader and the same procedure worked successfully.
Incidentally, the SDDR-31 had no problems writing bootable disk images that included a partition table. The trick was making a bootable card from scratch.