Success! Well, some success.
As well as the aforementioned Burberry trousers, I bought a pencil skirt and top from Wolford, of all places, both in a really lovely petrol blue. Pencil skirt is like this (although I think it's called something different, it's basically a jersey tube), and this top. But, most excitingly, I got a bag! It's the AH maxi zip satchel (first pic in that link). I think SE linked it a while back, but it looked too red for me, and also too expensive (was obviously much cheaper at bicester). It's actually a really nice burnt orange, basically the same colour as my crappy River Island pleather one that I love that is falling apart. It's a bit casual for a proper formal work bag, but given that most of the time I'll be working I'll be in my studio with no need for a handbag, I figured it would be fine for now, and I'll worry about tracking down a smarter one some time in the future.
The only thing I was really hoping for that I couldn't find was a nice plain cotton shirt (which I had built several imaginary outfits around), but I can live with that - might pop somewhere for some late night shopping if we finish training early one day.
I also tried on this DVF which I am slightly wondering if I should have bought. I could't decide if the print was a bit fussy for me, but it was a beautiful shape. Also some beautifully cut DVF trousers, but I was between sizes and couldn't quite decide. And was in a bit of a rush to get home by that point.