Spot on with the HS125, it is indeed G-AVGW which sadly crashed on to Vauxhall during a training flight on 23/12/67.
The DC-3 behind it was G-AMSN, still in the basic colours of Mercury Airlines who had ceased ops in Oct 1964. It was registered to a Lord Peter Calthorpe of Jersey on 22/11/65. I never saw it fly, and have no idea how long it had been at LTN. It was sold in the USA as N3455 on 28/12/67, then in Egypt as SU-BFZ and Ireland as EI-BSI before being restored to G-AMSN for Aces High on 13/11/89 (was still N3455 at North Weald Aug 1995). It moved briefly to Sandtoft in 1998. It was then back at North Weald and used in the TV series "Band of Brothers" in 2001. After being moved to Redhill on 24/6/04, it then went to the D-Day museum at Carentan, France in October 2004. Currently reported as being converted to a flight simulator.
The BMA is DC-4M G-ALHY and was operating the evening Jersey flight. This aircraft was withdrawn from use at East Midlands later in 1967, getting broken up there during 1970.
Not sure whether the Autair HS748 is G-ATMI or G-ATMJ.
Here's another one
G-ANBI 15/7/67
This is the view from the original spectators area to the left (south) of the terminal. Apart from the aircraft, it shows the area that became a grass (mud!) spectators car park in the summer of 1968.