Rob> -r-xr-xr-x    1 root     root      3975775 Nov 11 02:48 netbsd.macppc
Rob> -r--r--r--    1 root     root        58284 Nov 17 20:35 ofwboot.elf
Rob> -r--r--r--    1 root     root        55444 Nov 17 20:35 ofwboot.xcf

  It seems me you have picked up netbsd.GENERIC.gz (gunzipped) for
netbsd.macppc.

  You have to pick netbsd.GENERIC_MD.gz instead.
The name may be netbsd.macppc or netbsd.GENERIC_MD.gz (the name as it is) or
netbsd.gz. You don't need to gunzip.

The best practice is 'cp netbsd.GENERIC_MD.gz netbsd.gz' when you create
CD. In that case you just need
boot cd:,ofwboot.xcf

Good luck,
---
(Makoto Fujiwara)
http://www.ki.nu/software/NetBSD/iBook2/
http://www.ki.nu/software/namazu/tutorial/