“…was there a separate 9.1 install for the b+w g3 series? the 450 was in the second release generation second wave of b+w g3?”
Unaware of such a thing.
Only thing that I can think of offhand, was a firmware updater once offered. But don’t think that’s necessary in your case, as it does accept and run OS 9.04 — just fine. Wouldn’t hurt to check though, I suppose.
I do wonder what expansion cards might still be present inside when you attempt the 9.1 update? You know, the old hoodoo voodoo of removing everything except what is barely necessary for basic minimum function… when installing or updating the OS? (I’m thinking specifically of that SiL 3112 card AND of course anything else?) Yes, now I am clutching at straws.
And I’m not exaggerating when I say that I spent many hours (totaling many cumulative DAYS) fighting and cursing my original B&W - after my original installation of OS X. It actually led to me giving up on Macs entirely for about ten years.
I assume that your original, stock 450 MHz B&W came with the Revision 2 motherboard, featuring the 646U2-402 CMD chip?
If not, well then there’s another possible fly-in-the-proverbial-ointment. (More clutching at straws.)
Really, if you don’t actually have a specific need for OS 9.1 — skip the sequential ritual and go straight to OS 9.2.
AND possibly related… did an OS 9.2 Mac mini install here last night and upon reboot afterwards, got that freeze as it was attempting to load AirPort extensions, etc. No happy Mac icon, just a white screen freeze like the B&Ws have done here in the past. Command+option+esc got me out of that and then into the Setup Assistant (which I also skipped with that same keystroke combo). Then, manually powered down and rebooted with Command+ Option key combo in order to rebuild the desktop and all was then a-ok and with a full, clean boot / with no hangs or freezes.
AND there’s no mention of that Airport thang until after the Command+option+esc sequence. Just a dead white frozen screen.
But believe me, I completely understand the never-say-die desire to get the sequential route to work as it should.
I hope that you solve it! (Do keep us all posted?)