Quite a bit more progress compared to the last photo.
I cut out a part of the original PCB so I could reuse the potentiometers and connectors. At that point I didn't know if the pots work right or not. Luckily later on I found out that they were mostly good, nothing some contact spray could not fix :D

One of the inputs is usable now, and there's a small boost stage too. I think it was buffer at that point, I no longer remember even though it was yesterday lol