So, I had a little time today to do some more work on the system. I had mentioned that there were distant spots of corrosion, nowhere near the battery in the prior post. Well, come to find out, it wasn't from the battery. Evidently, a mouse had gotten inside this computer, thanks to the prior owner not replacing one of the expansion bay covers, and proceeded to crap and piss on random spots on the motherboard. Disgusting. I found few mouse turds scattered around the motherboard. So, it got a total washdown with isopropyl alcohol today.
I had to remove a dozen of the EMI filters on the SCSI and parallel ports to address the corrosion the vermin had caused.
I made a catalog of all the required parts to replace corroded components, and, ordered them from Mouser today. Next time I update, I will have been in ground-plane hell desoldering all of these passives and ICs damaged by the battery. I have a love/hate relationship with the A3000 due to how hard it is to desolder and resolder components due to the very large copper ground planes it has.
After component removal, I can sand the damaged solder mask and clean up the copper underneath, then recoat with some UV cured soldermask repair material.
One thing I'd like to mention is that if you are treating a battery damaged Amiga, make sure you flip the board over and check the vias on the other side of the board, near the battery area. I found six of them with corrosion from the Varta death fluid leaking through them.