Hello,
Thank's for letting us join and also to share your experiences. We're not in the UK but in the South of France near Nimes. After towing for some years a boat behind now I wanted something more light for the short weekend trips (is not cool going in the winter for skiing and climbing up into a boot to sleep ;-)
This old Triton I had rescued from an elderly gentleman who is no longer allowed to pull a trailer behind his car because of his age. He could not separate from the Triton for over 10 years and kept him carefully in a shed. Yes, the frame and everything is completely rust-free (well some marks but nothing whatsoever serious) ... For a 40 years old caravan, it is already amazing how well the received. Strange, but it's again the same experience I've made with my old Land-Rovers Discovery One, - you know this relic of the Solihull factory in the West-Midlands with real quality standard, and this little silly Freelander.
Well, in the past 40 years there have also been useful technical innovations to make life easier. It does not have to be a twaddling Google-box, but solar, LED and shower would be a step in the right direction. So, thanks to Aron here, I'got already an idea that the whole old Electric should be out and everything on 12 V and solar rebuild, then on 220 via transformer from a VRLA battery...