File:HM The Queen Visiting The Post Office Tower On 17 May 1966.jpg
The frontage has been heavily modified, but you can see the concrete panels on the first floor are still intact.
The Queen is in powder blue. Of the group of three in front of her, Tony Benn (then Postmaster General) is on the right.
The street light in the way features a GEC Z9455 top-entry SO/H luminaire on a 25ft column.