I replaced the rest of the harness connectors and added the key pins - looks good. I also replaced the zener diode at ZR2 with a 4.7v like Braedel does, in the hopes that the settings won't get lost randomly during power cycles due to using a switching power supply. I wasn't sure which wattage, so I ordered all 3 available from Marco, and used the 1 watt since it looked closest to the original.
The pins on the main PCB had major cold solder joints, so I reflowed those with new solder, and they seem to be holding. I might try replacing the header pins myself, but more likely, I'll send it off to have it done properly.
This is how I've been monitoring it for the past week so I don't climb the stairs 100 times. A nest cam.