Updated: Aug 4, 2021
Midland International at Gatwick Airport I do have a photo of that branch, which I took on the way to Corfu in July 1985.
Even more bizarrely, when I was at Barking branch in the early 1990's I did a ledger (encashment) call for one of our customers, who was trying to cash money at Gatwick.
As many will remember, the encashment book had a sequential series of numbers to authorise the encashment.
I wrote out all of the details, and the number next in line for this Gatwick Airport encashment was... 747.