Definately Syerston, I was there.
The Vulcan was a test bed from Hucknall flying with Rolls-Royce Conway engines and was I believe simulating airline service prior to entry of the Conway in BOAC 707s.
The fast run for the airshow crowd was with the vulcan in a rolled to starboard attitude presumably to show off the delta.
I recall the upper skin rippling proir to failure.
As for airshows at Newton, there certainly were some in the 50s. I saw an F86 Sabre break the sound barrier there at one display.