In 1979-80 I made multiple business trips to Southend, for which the hotel provided was the Airport, seemingly still there on the west side. Parked right behind the room was the hulk of the last Carvair, Plain Jane, which seemed just abandoned there. I think the aircraft museum that used to be there had their eyes on it, but eventually the whole museum closed. There was no fencing, just walked across to inspect the aircraft a few times. The hotel was right by the 06 threshhold, and at about 1am there were a couple of BAF Herald night freight departures to Europe which would spool up and wake everyone up. Noisy old Darts.
Must have been about 1984 I was at the hotel again just when BAF had bought the old BA Viscount fleet, in the week there a different one used to turn up each afternoon, I believe being ferried in from storage at Cardiff. Presumably the crew went over each morning on the train or whatever and ferried it back.
There was a great account in Propliner magazine in the 1980s by one of a BAF Herald crew about a fascinating charter, including a couple of dicey moments, to support the "Paris to Dakar" road rally, a significant sporting event of the era across the Sahara. Presumably the experience of subcharters to Air Algerie described above served them well.