I've a bit of a wait for BOP's rear springs, so I'm having a go at one or two other things "whilst I'm on" (as you do...

). I'm hoping to get everything done in the 6 weeks-or-so window that I have. Otherwise, it will drift & the car will hog the pit for months.
The de-dion gaiter was split, so I took the tube off & was going to put some new seals in whilst it was apart. Unfortunately, I think the seals must have been 'new old stock' because they were a bit hard & I couldn't get the inner tube back in without the seals distorting:
I had to put the used seals back in

oops

& all is now fine. I have filled the tube (up to the filler neck) with some thicker oil I got for he Alfa's steering box, so there shouldn't be any leaks. The gaiter wasn't actually leaking when I took it all apart, so the seals were good. In fact they hadn't been in all that long, so I was just doing a 'belt & braces' job with buying the new ones.
Access to the underside is easier at the moment, particularly on the near side as I've removed the exhaust back box which needs replacing. I've repaired the often-perished rib inside the rear wheel arch:
But now, of course, "there's more" (as the late Jimmy Cricket would say). This is the vertical section near the bump stop:
Loose underseal has certainly been the culprit here, trapping water for a long time.
None of these areas carry much structural weight & were pretty thin pieces when new. However, "I may as well whilst I'm on.."

. Even with the pit & with various bits removed, they are still quite difficult sections to get to (& to weld properly). We'll see how it goes.