I was hoping to post a very happy note that the kitties had arrived, however there's a problem with the very stringent requirements they have to meet before being allowed into the UK. Unfortunately the vet in the US neglected to give them one of the required treatments. So they have arrived to the airport safely, however they are stuck for another 24 hours until the treatment can be administered.
So far most of this process has been a complete nightmare from start to finish. I'll update in more detail later on, but big thanks to everyone who's been involved in getting them here - Hank and I will be tremendously relieved once we've seen that they are safe and sound at home.