Slightly aside, but the Trident (LHR On this thread) has had a satisfactory sum spent on it by various companies including BA and was maintained for towing and ground training. However, one of the reasons for its demise is its undercarriage problems that even after replacement only some 4 years ago has been declared unsafe and is another reason for its removal.
I would be interested to know just what sort of issues the Southend Vulcan has with regard to undercarriage testing as all these problems soon mount up and despite what some brothers have stated parts and spares are not easy to come by even if you can find anyone skilled enough to make them.