I got a note from them recently as I'd bought the prior volumes of the BRM series from them. The offer was to get a copy of Volume 3. I did this, and the book arrived fairly promptly (allowing for being in the US). They were'nt unfortunately able to match the number, although they didn't guarantee that. In an exchange of correspondence I had with them they said that had a lot to do on the new web site and (for example) they'd be able to supply David Bull Publications.
I was glad to see them back, service seemed good, but from a US point of view they're quite a lot more expensive than some other outlets over here.
I also might have teased 'Elizabeth' a little as she sent me a link with yet another variation of their URL
www.millhousebooksexhiits.com
!