A bit of digging has disclosed that the Comet clubhouse fuselage I referred to earlier in this thread was the second prototype G-ALZK, with some additions from an unidentified ex-RAF Comet.
I must admit that it seems strange that major parts of the world’s first two purpose-built jet airliners were sent for scrap as late as the late 60s/early 70s but ho hum, what’s done has been done.

https://abpic.co.uk/pictures/view/1194223

By the late 1960s, there were four Comet 1 remains to be seen at Farnborough. Two cocooned fuselages, a fuselage in BOAC markings in use as some sort of clubhouse, and a truncated centre fuselage.
In the early 2000s I exchanged a few emails with a Comet researcher. Unfortunately, they’ve vanished into an internet black hole, so I’ve got to go from my memory.
The gist of the information  was that F-BGNX, now at Salisbury Hall, was one of the cocooned fuselages. The other cocooned fuselage was identified, although I’ve forgotten the details, and the incomplete fuselage was reckoned to be a surviving chunk of the prototype G-ALVG. The identity of the clubhouse was still a mystery, though.
I took the attached picture at the 1968 Farnborough, with the possible remains of G-ALVG in the background . The next show I attended was 1974, by when there was nothing to be seen apart from a fuselage in the far distance somewhere at the Laffans Plain end.
Can anyone else throw some more light on things?