I just browsed through some old video tapes. By chance I came across an old episode of 'Battle for the skies - The History of the Royal Air Force', episode 'A Vicious Sting'.
Amazon.com: Battle for the Skies - The History of the Royal Air Force [VHS]: 1@ Shv Dd2252-Dd2257: Video
After about nine minutes there is a shot of only a few seconds in which someone flies a Spitfire in front of a camouflaged hangar in a nicely held sideslip. In the next shot it banks hard going the other way, all well below roof height.
No guarantee of course it was piloted by Alex Henshaw, but apparently footage like this still exists in an archive somewhere.