It sounds like you are capable of doing the work and looking for suggestions; I can only speak for myself, but I would look at this strictly as a factor of time. You are looking at removing and replacing roughly 40 corroded parts, many of these are not going to come out clean due to the corrosion and damage can be expected to some of the thru holes, the alkaline then needs to be neutralized and the board sanded to remove the corrosion and allow for the soldering of new parts, all holes that pass connections to the opposite side of the board need to be tested and repaired.

Personally, I wouldn't make the time commitment to repair the board and would just replace it; however, since all of your questions end with "Take it out and follow terry B's damage guide and replace all affected components." I would recommend doing this sooner rather than later, as the damage is going to just get harder to fix the longer you wait.

Hope this helps.

Worst case scenario, you cant repair it and are out a board...on the upside if you end up having to replace it, the old one will make a good practice board for learning on. With the relatively low cost of this board (without CPU, ROM, ASIC) I doubt you would find anyone that would repair it for less than 80% the cost of a replacement.

If you are cost conscious, have time to do the work and want some soldering practice, an option is to build your own MPU; depending on your skill level and how detail oriented you are, it will take roughly 10 hours to build one. The soldering time is less than an hour of this, most of the time is spent identifying and bending components, cleaning, and inspection. The build cost is just over $100 and the best thing about this is your machine is operational and you can work on this a little at a time until its finished...see this thread for details: https://pinside.com/pinball/forum/topic/twobits-wpc-mpu-complete-assembly

I will make this trade for you for free

WOW! You did a fantastic job on this board; not only does the board look great, I don't see a single broken trace anywhere which can be extremely difficult to pull off on a corroded board.