Sepia Astronomers

When cleaning out an office here in the Astrophysics Group in the Physics Department at Imperial College, we came across this photo:

The background is the Mark I telescope at Jodrell Bank, and the man in the middle with the notebook has been identified as either Fred Hoyle or Francis Graham-Smith (which is more likely now that I look at it — thanks, Peter!). Do my astronomy colleagues (or anyone else) have any more information?