The iBook is Repaired
Success! Trying though it was at times, I've replaced the hard drive in the iBook and now it's contentedly churning its way through a Mac OS X installation. And I only have a very few little leftover bits and pieces! :)
I must attribute grand levels of credit to PB FixIt for their excellent guide. It was clear, well-written, well-illustrated, and even supplied much-needed emotional support at the most difficult points of the operation.