Oh my... looking at picture #7 reminded me of the most difficult/tedious part of the new studio build I was blessed to do at WFIF in 1997.... building all those Molex connectors, and bringing them out to punchblock. I was SO GLAD I did it, tho, any time something needed to be changed or added! :)
Since my departure in 2007, I'm sure their new Engineer is thankful for the punchblock! ;)
As for getting that sad little board working, all I can offer as a suggestion is to bring it back to Factory Spec. before doing anything else. IOW, disconnect and remove ALL of those mods. Once the board is back to Factory Spec, it will be MUCH easier to diagnose using the manuals and schematics. THEN, you can add any mods the new owner needs.