Phill hit it on the nose when he wrote,
 The really important thing to remember about SGI
machines is that the
contoler's SCSI ID is 0 and not the more conventional 7, this did seem
to trip up a lot of people :) 
Something I read had me firmly convinced that the machine defaulted to a boot drive on ID
0.  On the downside, I feel sort of dumb, but on the upside, the machine sees the drive
now :)
Thanks a lot to Phill and Dan for helping me out.  The machine makes a great boot chime,
which I recorded and posted here:
http://www.nuvistor.org/content/powerindigo2.mp3
John