You may want to consider if you can run the computer without a battery. The 660AV will not start without a battery. However a G4 iMac boots fine without a battery - you just need to set the clock
Most will boot normally, but all PRAM settings will be at their defaults. In which case, using TechTool might work, since you can save and restore PRAM settings.
Last weekend I picked up a few machines, and this was the sole Maxell victim. Macintosh LC.. look at all the caps that have literally been disolved! Literally nothing worth salvaging on this one.
The socketed ROMs look mostly OK? might just need their legs sanding
Maybe hot air off some chips from the other side of the board? I'll agree though most of that looks toast. RIP