Thank you all.
Yeh, I know what & where it all goes having taken my engine & box out 2x before (Once for box, 2nd for turbos). I have an almost identical pic of my box & motor on the garage floor.

It's just a question of working out the easiest way to do it. On stands too, I don't have a lift.
I don't think downpipes need to come off - although even if they needed to, I'd expect all the fasteners to come apart easily having only been together for a couple of years and I replaced em all with new & lots of nickel grease. (Too hot for copper, don't ya know!)
I plan to try re-soldering the sensor boxes first, but have got a pair of brand new sensors in the stores in case they're needed. Oh, and a 2nd spare used set...
(I've actually got quite a lot of spares on the shelf now - I figure it's not too long before spare parts start to become quite hard to get....although perhaps to prove me wrong, the manufacturing date on the new EGTs is 2013).