I'm glad to hear you are making progress. Do you have more photos of the damaged area of the board? In your third pic there are definitely a couple rotted vias. Have you checked what they connect to, and come up with a plan to repair those? If the via just goes straight through the board and does not connect to any internal layers you can run a thin bodge wire through the hole where the via was. If the via connects to one of the middle layers you might have to get more creative.
I just finished most of my SE/30 build today. When I pulled the RTC off my donor board a couple days ago the bottom half of two legs broke off due to corrosion, I had to bodge those. Then when I pulled the video ROM from the socket on the donor board, one of the legs was too corroded to come out of the socket so the bottom half of that leg broke off. Fortunately, the broken pin (28) and neighboring pin (27) both went to +5V, so I was able to just jumper the pins together. I look forward to hearing about your progress.