Brilliant post, and excellent work!
Just a quick heads up, a member of another forum had an issue with the XPart-issued FC112187A bolts for the rear arms - when torqued to spec one sheared.
It was a fairly recent issue - wouldn't want you fitting them from the same batch if affected, that's all.
I've got a detailed description of the issue saved if it's of interest, but I won't post it publicly here.
A shame the rear arms were too far gone; the quality of the originals far outweighs any of the current 'options' so I'm a fan of saving them where possible.
Absolutely lovely to see such in-depth work being carried out to one of our fine cars
Edit: just to add, I'd fit the subframe and then everything to it. They're incredibly heavy when fully built-up.