Ok so now I've got your attention here goes.......
I have potential to buy a virtually mint Bongo shell (hardtop) for utter peanuts which is identical to mine in every way apart from no rust/dents. The shell will be virtually totally bare apart from windscreen and probably dash etc. The underside hasn't been undersealed and is totally clean with only very light surface rust in places. I have seen under it on a ramp and stripped down and it clean and rot free, newish really. It would be a shame to see it squished!
My grand plan is to prepare the shell underneath fully and swap all the parts over adding a few tweaks to suit my purposes.
On a ramp/workshop if I can borrow one (I am dropping hints to my brother but not sure if he will relent) I could sand down and paint the underside and arches then underseal it totally as it is bare. Then it would last a lifetime

I would remove the rear carpet, possibly ply-board the floor and then put vinyl down. We have dogs and would like to be able to wipe down the floor as they get soooo muddy! I would then just have the middle seats as I do now.
I have a few performance plans for the engine using a custom chargecooler kit I have gathered together and have had fabricated which would be easier to fit/problem solve when the Bongo is apart. A scratch built air-box will be made.
I think the new shell is originally 2wd (not that it matter although will say in the log book) and might consider converting mine to 2wd for fuel economy purposes and will also be slightly lighter and leave more room for pipework for my engine plans. I have a limited slip diff and although with my present set-up it is fantastic in the snow it doesn't snow much in Cornwall!
I am thinking of using lowering springs but also look into raising the engine/gearbox to suit to keep ground clearance as I live in an area with lots of speed bumps/ramps. On a bongo there are only 2 engine mounts which are on a hefty crossmember and one gearbox mount which hangs it from above, modifying these should be straight forwards. The reason for lowering the Bongo would be to lower the centre of gravity as bongos do roll a bit in corners and also to reduce the frontal area to help fuel economy.
I am umming and ahhing about keeping the air-con as I would have to be degassed and re-gassed and it would be fiddly and faffy to remove and replace but it is nice to have on a run on a hot day. Removing it may help increase economy a smidge (no belt to drive although I tend to remove the belt in the winter anyway) and it would be slightly lighter and improve airflow to the engine radiator. If I did remove the air-con I would consider moving the alternator to where the air-con pump is to better route the air intake to the turbo.
If I can get garage space then the prep work on the shell I can do at my leisure within reason but once I start swapping parts over this is when the heat will be on. Our Bongo is our only transport and my wife has a bad back which means she struggles in any other cars hence wanting to keep a Bongo long-term.
I would I supose need to take a few days/a week off work to do the swap. Has anyone done a similar swap before. In my head I know I under-estimate the complexity and time consuming slog that it will be. I know a shell can be stripped in 2 days but will it go back together so easily?
I am also wondering how to move the shell about when it is being worked on - how many people would it take to move a bare shell? I am thinking through ideas of a frame and castors, any suggestions?
Also does anyone know of any work space local to Plymouth/SE Cornwall?
Any thoughts/suggestions? Russ