I don't think lamp boards are really worthwhile to repair when they have any significant battery damage. Maybe save the large chips if possible (if they're clean), and then recycle it.

The MPU isn't the worst I've seen. It's reparable. The header pins would need to go, though. If you do (or can do) the work yourself, it may be worthwhile. If you can't, it's probably not economical to send it out for repair since it's not a particularly expensive (aftermarket) board.

The wrinkled masking on the traces on the entire board is normal.

Vinegar doesn't actually do much of anything. I use Zep now. It's more acidic and you can actually see a chemical reaction with the alkaline leakage, which actually removes most of it.

https://pinside.com/pinball/forum/topic/stripping-battery-corrosion-with-a-strong-acid

Thanks, glad you're happy with it

It was mentioned in a lot of places. I used it too because it was pretty much the go-to approach. But I always kind of wondered how effective it actually was since I could never see the vinegar actually do much of anything.

Once I saw zep work and clean off the alkaline residue, it was obvious that vinegar was not very effective. It simply wasn't acidic enough to counteract the alkaline.

So, as time goes on, people try new things, and better techniques sometimes surface to replace older ones.