Guys it was nearly half a century ago. Yes it may well have been Southend and judging by the curve in the apron it probably was. Very likely the same day as the previous picture of G-AICT.
I think that Sabena had two freighters registred OO-PAU and AV if my memory serves me correctly. EDIT: My memory has got it wrong again. G-APAV was painted in SABENA colours.
The Carvair in the middle of the line would also tend to suggest Southend.
I have a couple of 'off thread' photos of other aircraft taken at the same time and suffering the same degredation of picture quality that were definitely Southend.
Thinking about it Ferryfield also parked the freighters nose in to the terminal and the aircraft were pulled out tail first by a tractor. So Southend it must be.