Apple IIGS, A2S6000. This is the computer that prompted me to write about the exploded Maxell Pram battery.
While I did not take a photo when I first discovered it, the power supply blocked the worst of the damage and kept it pooled around the battery and slot 1 area. It has been completely disassembled, acid sopped up and then the parts cleaned with baking soda, white vinegar, etc. and rinsed thoroughly in isopropryl alcohol.
I finally put it all back together today. It boots, passes the self test and the Apple Diagnostics numerous times.
Inside, you can see the areas - especially on the inside of the cover and the back panel where cleanup had to be done, as well as an area of the power supply (not pictured). There is a photo of the area of the motherboard affected by the battery. The ports are all working. Slot 1 is currently working. Battery holder has been removed.
The outside of the case has medium discoloration - lighter area on top where the monitor was. It has all it feet, no slot covers. No additional memory, just the 1 MB on the motherboard.
Sold As-Is! While I cleaned it up to the best of my ability, I cannot guarantee that it will continue to work.