Today's progress
I solved the air gap problem so I don't lose the cold air from the fridges with some well-placed styrofoam. Water spigot installed, but not hooked up.
I now need to wait for my replacement drip tray (longer) and the line for the drain. Then I can hook it all up and call it done (except for a bit of trim needed on the bottom of the cabinet).
I'm pleased with this project, in that it actually went as expected. Everything should be good to go for the housewarming.
