I just bought an Anita underwired nursing bra from nursingbra-shop.co.uk, they ask you to recommend them if you are happy with the service, and I was, so I am doing! They use Mumsnet bra intervention compliant sizing, the bra arrived within 48 hours, free delivery, and they are happy to exchange or refund if it doesn't fit. I have binned the ugly bras I was wearing and ordered more in my new size of 32F
Suddenly my clothes look better and I have rediscovered a waist. Hurrah!