After numerous fruitless attempts to install OSX back onto the wounded Powerbook, I have started attempting to install via SCSI dock mode; this worked over a year ago when the machine lacked a screen.
The installation problems are most painful, as due to the creaky speed of the processor and the 2x CD drive, it takes the machine about 4 hours to get to the point where it fails to complete the process.
Revised ETA for actual return to full-functioning status: 72 more hours from here, November 1.