Unless you're an absolute Pro - drop this plan.
It needs a complete rewiring of the keyboard connection, the trackpad, you will need a longer display cable and the peripheral connection and the optical drive.
A logicboard of a G4 iBook 800 will fit in if you remove the frame and you may use the G4 keyboard because of its similar size. The Clamshell has no built-in fan, so there would be a heat problem, because the Clamshell case is not built for this.
Start with a desktop Computer project - e.g. intel mac mini in a G4 Cube .....
well i won't matter all i can salvage is the case and maybe the keyboard if the water damage isn't to bad.
the motherboard is shot, the screen is cracked, the battery is corroded and leaked out, and the cd drive hard drive are corroded and rusty. so all i have is a case that needs to be empted and cleaned.