Here is a short video with a new 1024x768 screen. After a prolonged boot time the resolution switches from 800x600 to XGA, because of a firmware hack.
You need a Clamshell iBook with a LG LP121SA 800x600 LCD panel (15% of total number, IBM and Samsung were used more often)
How do you find out? The software switchresx 3.8.7 (for 10.4 Tiger) will help, you only have to run it once. The Export EDID function will create a text file which contains manufacturer information about the Display.
Buy a known-good screen from a white iBook G3 or G4. Swap Displays. LG display cable from Clamshell is pin-compatible. Use hot glue to fix display in the right position. Apply open firmware hack from / (a little bit tricky) DVD playback on a 466 mhz or 366Mhz (restricted) system possible with VLC player 0.86i PPC. Brightness via freeware "Brightness Control" splasm software.
Another option is to use an existing Samsung display cable with an "LCD Cable Converter 25mm 20 pin convert to 22mm 20 pin 26 mm" which i had bought at pchub.com