Successfully (so far!) changed out the 266 Mhz CPU with the 450 Mhz CPU from the dead Blue and White.
Due to the nature of the AIO logic board/jumper settings, the CPU is running at 466 Mhz. I can kick it up to 500 Mhz, but for the time being, this is fast enough for me. If it's stable over the next few days at 466, I'll kick it up to 500 Mhz.
If/When I am able to get the G4 I want, this All In One will be properly reconfigured as the backup machine. If possible, I'll have it backing up the Eudora address book and mail folders on the G4 once a day, along with the browser bookmark file.
I can run OS X, 10.2 on this machine. 10.2 at 500 Mhz, with sutiable versions of Eudora, FireFox and Graphic Converter would go a long way towards making this a suitable long term backup machine in the event the G4 craps out.
Another option is to add this AIO to the local network and use it as the printer and scanner interface/Photoshop machine. I've a Wacom graphics tablet that isn't supported under OS X, but works wonderfully well under OS 9. A CD/RW would also go well installed in the AIO.
I am SO going to need a bigger desk if I do this.
Aout the only really annoying thing is that I can't download pictures from my camera via the USB cable. I need to get a memory card reader. Looks like I'm off to Micro Center to get the cheapest one they have that'll read SD cards.
In other news, I picked up a used and working FIreWire USB hard drive enclosure, complete with 70 GB hard drive. Works fine. I think this'll be the system backup drive.