paul> scsi-int/sd@0:0 was OK for the installer to work with but how do I boot from 
paul> it? 

Does this mean you have CDROM drive at scsi-id = 0 ? 
It seems to me 9500 has internal HD as scsi-id = 1.

If above is true, set as
   boot-device  scsi-int/sd@1:0
That's all you need ( as far as scsi id is correct).

paul> boot-file           netbsd
You don't need this set, but it may not hurt anyway.
To clean up,
   set-default boot-file
---
Makoto Fujiwara
http://www.ki.nu/software/NetBSD/iBook2/