BlitzRommel, I recently had the, uh, pleasure, of resetting the password on a BS450-24T, which may be similar enough for my experiences to matter. What I learned in that exercise is that the NetICs password (it is a password, not a hidden thing you type some other time, console only) only works in the pretty much original firmware version. So try downgrading the firmware.
How do you do THAT? Well, with the switch I had, I hooked a sniffer up to a port, powered it on, and found that it was sending some management packets out once it booted, and those packets' source IP address was clearly the IP address that had been configured on the switch. And luckily, the read/write SNMP community string had been left as "private," and the BayStack MIBs contain variables through which you can set the TFTP server IP address, filename, and then tell it to download an image. So assuming that this switch has an IP address configured on it (good chance), and its r/w SNMP string is left as the default of "private" (crap shoot, really), you should be able to downrev the firmware that way.
Do a Google search and look around, and you'll find the URL to an old ftp site at Bay where every released firmware rev seems to be archived. Nortel's web site only has the modern firmware, you need the old version. In my case, it was a 1.4 or something - 1.x.
There is a second way to do this, you can call Nortel's support and give them the MAC address, and they can generate a back-door password for you. When I called Nortel's support, I was told that without a support contract, they'll happily answer questions for $300/hr, 2 hr minimum. I was in a good mood and politely declined, but still... no way I was going to spend $600 to fix an old switch when I can get a better one all around from Dell for $400 (PowerConnect 3324). Charging for per-incident support really sucks but is becoming an industry norm as margins thin. But the egregiousness of their support fee definitely will stick in my mind the next time some customer wants to buy new Nortel gear.